The Washington-based think tank estimated that combined military casualties have exceeded two million, with Russian forces accounting for the majority of the losses. The assessment said Russia has suffered about 1.4 million casualties, including an estimated 400,000 to 450,000 troops killed during the conflict.

According to the report, Ukrainian forces have sustained between 525,000 and 625,000 military casualties since the war began. The study estimated Ukrainian fatalities at between 125,000 and 150,000 personnel over the same period.

CSIS said Russian military deaths in Ukraine now exceed four times the total number of U.S. military fatalities across all conflicts fought since the end of World War II, underscoring the unprecedented human cost of Moscow’s campaign.

The report also suggested that the imbalance in battlefield losses has widened in recent months. It estimated that the ratio of Russian to Ukrainian casualties likely reached approximately eight to one during the first half of 2026, indicating significantly higher Russian losses as fighting continued across multiple fronts.

The study provides one of the latest independent assessments of military casualties in the war, as both Moscow and Kyiv disclose limited official figures and wartime casualty estimates remain difficult to verify independently.

Russia launched its full-scale invasion of Ukraine in February 2022, triggering the largest land conflict in Europe in decades. Since then, intense fighting has continued across eastern and southern Ukraine, with both sides relying on drones, artillery, missiles and entrenched defensive positions as the conflict has evolved into a prolonged war of attrition.

Independent casualty estimates vary because of restricted access to frontline areas, differing methodologies and the limited release of official military data by the parties involved. Neither Russia nor Ukraine regularly publishes comprehensive figures for battlefield losses, making external assessments by research institutions and intelligence agencies an important reference for measuring the war’s human toll.

The CSIS report focused exclusively on military casualties and did not include civilian losses or broader humanitarian consequences resulting from the conflict.

Moscow Mayor Sergei Sobyanin said on Monday that air defence systems destroyed almost 60 drones headed toward the Russian capital. Emergency services were dispatched to locations where debris fell, though officials provided no immediate details on casualties or damage.

The attacks prompted temporary flight suspensions at Moscow’s Sheremetyevo, Domodedovo, Vnukovo and Zhukovskiy airports before operations later resumed, according to Russia’s aviation authorities.

Russia’s Defence Ministry said a total of 301 drones were intercepted overnight, including over Russian-controlled territories in occupied areas of Ukraine. The latest wave of attacks followed renewed Ukrainian strikes last week on Moscow’s only oil refinery, one of the most significant assaults on the Russian capital since the full-scale war began in 2022.

In Ukraine, regional authorities reported civilian casualties in several areas following Russian attacks.

In the northeastern Sumy region, prosecutors said a drone strike killed three members of the same family — a 13-year-old boy, his 36-year-old father and his 73-year-old grandmother. The boy’s mother and two siblings were injured.

Further south, a drone attack on the southeastern city of Zaporizhzhia killed one woman and wounded three others, regional governor Ivan Fedorov said.

In the Odesa region, Governor Oleh Kiper said a Russian Iskander ballistic missile struck an agricultural facility on Sunday evening, killing one person and injuring three others. The attack sparked fires involving vehicles and fuel storage tanks.

Security concerns also intensified in Crimea, the Black Sea peninsula annexed by Russia in 2014. Sevastopol authorities cancelled all outdoor public events on Monday and ordered street lighting to remain switched off as a precautionary measure.

Governor Mikhail Razvozhayev urged residents to reduce electricity consumption amid growing pressure on regional energy supplies. Authorities have also restricted fuel sales to government agencies and essential services after repeated Ukrainian strikes on logistics routes and energy infrastructure contributed to shortages.

Ukraine’s navy said Russian drones also targeted commercial shipping in the Black Sea overnight, damaging three merchant vessels.

One of the vessels, the Panamanian-flagged dry cargo ship Victress, operated by Turkey-based Rana Denizcilik according to shipping data, sustained significant damage after being struck by a drone. Ukrainian Deputy Prime Minister Oleksiy Kuleba said a 58-year-old Egyptian crew member was killed and eight others, including Turkish and Indian nationals, evacuated the vessel aboard a lifeboat.

Kuleba said two additional merchant vessels sailing under the flags of Palau and Belize were also attacked but continued their voyages without reported casualties.

The incidents underscore the continued risks facing commercial shipping in the Black Sea, where attacks on ports, vessels and export routes have become a recurring feature of the conflict and have disrupted regional trade since the war began.

The latest exchanges highlight the growing use of long-range drones by both sides as the conflict increasingly extends beyond front-line battlefields and into major urban centers, critical infrastructure networks and international maritime corridors.

Kyiv’s military administration said four people were killed and 23 wounded in the capital, including a child, after overnight attacks involving ballistic missiles and waves of Shahed drones.

Interior Minister Ihor Klymenko said five emergency responders were killed in Kharkiv after they were hit by a second strike while battling a fire caused by an earlier attack. At least five other rescuers were wounded.

Authorities said powerful explosions were reported across Kyiv overnight, with civilian infrastructure heavily damaged. Several strikes hit residential areas in the city’s Shevchenkivskyi district, including a 25-story apartment building, while a market and grocery store also caught fire.

A nine-story residential building in the Obolonskyi district was also damaged after being directly hit.

Kyiv officials accused Russia of deliberately targeting civilian areas, while Moscow has continued to carry out long-range missile and drone attacks during the ongoing war.

The strikes also caused major damage at the Kyiv-Pechersk Lavra, a UNESCO World Heritage site and one of Ukraine’s most important religious landmarks.

Officials said a major fire broke out at the historic monastic complex, while Metropolitan Epiphanius, head of the Orthodox Church of Ukraine, said the roof of the Dormition Cathedral was damaged.

The Kyiv-Pechersk Lavra, also known as the Monastery of the Caves, dates back to the 11th century and includes churches, monasteries and underground caves. It has long been considered a major religious and cultural center in Eastern Europe.

The latest attacks came as Russia and Ukraine remain locked in a war that has entered its fifth year, with Moscow continuing strikes against Ukrainian cities and infrastructure.

Sergei Aksyonov said on Telegram that the strike targeted non-residential facilities in the Crimean capital. He did not specify the type of attack or provide further details on the targeted sites.

The reported attack comes amid continuing hostilities between Russia and Ukraine, with both sides carrying out long-range strikes on military, energy and infrastructure targets.

There was no immediate comment from Ukrainian authorities regarding the incident.Crimea was annexed by Russia in 2014, a move rejected by Ukraine and most Western countries, and has remained a frequent target of attacks since the start of the broader conflict.

Kuwaiti air defenses intercepted missiles and drones as warning sirens sounded across the country. Kuwait said the attacks violated international law and undermined efforts to reduce regional tensions.

Saudi Arabia, the UAE and the Gulf Cooperation Council also condemned the strikes, expressing support for Kuwait.

Meanwhile, Iran’s Revolutionary Guards said they had targeted an air base allegedly used in a U.S. attack on Sirik Island, without identifying the location of the facility.

Officials in Russia’s Belgorod region said a Ukrainian drone struck a vehicle in the town of Graivoron, killing one civilian. The attack was among the latest incidents affecting Russian territories bordering Ukraine, which have increasingly come under drone and artillery fire during the war.

In the neighboring Bryansk region, acting Governor Yegor Kovalchuk said a man was killed in a Ukrainian strike on the settlement of Belaya Beryozka. Local authorities did not immediately provide additional details regarding the circumstances of the attack.

Ukraine has frequently targeted military and infrastructure-related sites inside Russia, describing such operations as a response to sustained Russian bombardments of Ukrainian cities and regions since Moscow launched its full-scale invasion in February 2022.

The latest fatalities came a day after intense Russian attacks across Ukraine. Ukrainian authorities reported that at least four people were killed and more than 100 injured during overnight strikes from Saturday into Sunday, with the capital Kyiv among the areas affected.

Kyiv and Moscow both reported that Russia employed its nuclear-capable Oreshnik ballistic missile during the latest wave of attacks, marking another escalation in the use of advanced weaponry in the conflict.

The Russian strikes followed a Ukrainian drone attack on educational facilities in the Russian-occupied eastern Ukrainian region of Luhansk, where authorities reported 21 deaths and more than 40 injuries.

The conflict, now in its fifth year, remains Europe’s deadliest war since World War II. Diplomatic efforts led by the United States to broker a settlement have made little progress in recent months, with negotiations largely stalled following the outbreak of conflict in the Middle East and the resulting shift in international diplomatic priorities.

Ukraine’s State Emergency Service said rescuers were still clearing debris and searching for survivors in Kyiv’s Darnytskyi district after hours-long attacks overnight caused extensive destruction to apartment buildings and civilian infrastructure.

“Rescuers continue clearing the rubble and searching for people in the building in Darnytskyi district non-stop,” the emergency service said in a statement posted on Telegram, revising an earlier reported death toll of 16.

Images released by Ukrainian authorities showed burned vehicles, shattered residential buildings and emergency personnel working through debris in heavily damaged neighborhoods.

The latest strikes marked one of the deadliest attacks on the Ukrainian capital in recent months as Russia continues intensified aerial bombardments targeting cities and infrastructure across Ukraine amid the prolonged conflict.

Ukrainian officials have repeatedly accused Moscow of deliberately targeting civilian areas during large-scale missile and drone assaults, while Russia maintains that its strikes are directed at military and strategic infrastructure.

The attacks came as fighting along multiple front lines in eastern and southern Ukraine remained intense, with both sides continuing long-range strikes deep beyond battlefield positions.

The military identified the soldier as Sergeant Major Alexander Glovanyov, 47, who was killed on Sunday in fighting close to the Israel-Lebanon frontier.
His death brings the number of Israeli military personnel killed since the conflict with Hezbollah intensified in early March to 18, according to Israeli military figures. One Israeli civilian contractor has also been killed during the hostilities.

Fighting has continued in southern Lebanon despite a ceasefire agreement signed between Israel and Lebanon on April 17 that was intended to halt cross-border exchanges of fire and reduce the risk of a broader regional escalation.

Hezbollah entered the conflict on March 2 after launching rockets into Israel, saying the attacks were retaliation for the killing of Iran’s supreme leader in joint U.S.-Israeli strikes, according to statements from the group.

Israel responded with extensive airstrikes and later expanded operations into a ground campaign in southern Lebanon.

Israeli forces are currently operating behind what the military describes as a “yellow line,” an Israeli-declared security zone extending roughly 10 kilometers north of Lebanon’s border.

The latest casualty announcement came as smoke was seen rising from areas in southern Lebanon following reported Israeli airstrikes targeting the village of Choukine, according to AFP images from the region.

The ongoing exchanges have heightened concerns that fighting between Israel and Hezbollah could evolve into a wider regional confrontation involving Iran and allied armed groups across the Middle East.

Diplomatic efforts led by international mediators have so far failed to fully enforce the ceasefire or secure a durable de-escalation along the volatile frontier.

Valery Gerasimov said in remarks released by the defense ministry that Russian forces had taken control of 80 settlements and were pushing toward what he described as Ukraine’s “fortress belt” in the east.

The campaign is focused on the Donbas, where Russian troops are advancing toward a line of heavily defended cities, including Sloviansk, Kramatorsk and Kostiantynivka. Gerasimov said Russian forces were within 7 to 12 kilometres of Sloviansk and Kramatorsk and already engaged in fighting in parts of Kostiantynivka.

Russia is also conducting operations in the northern Sumy region and the northeastern Kharkiv region, aiming to establish what it calls a “security zone” along the border.Reuters could not independently verify the battlefield claims, and Ukraine’s military did not immediately comment.

Pro-Ukrainian mapping suggests a smaller territorial gain by Russian forces this year.Ukrainian commander Oleksandr Syrskyi said earlier this month that Kyiv’s troops had recaptured nearly 50 square kilometres in March, highlighting continued contested advances in what is Europe’s deadliest conflict since World War II.

According to Russian estimates, Moscow controls about 90% of Donbas and roughly 75% of the Zaporizhzhia region and Kherson region, along with smaller parts of other regions including Mykolaiv region and Dnipropetrovsk region.

Russia also retains control of Crimea, which it annexed in 2014, a move widely rejected internationally.The conflict, which began with Russia’s full-scale invasion in 2022, continues to see incremental territorial shifts, with both sides reporting gains amid heavy fighting.

The attack targeted a unit serving with the United Nations Interim Force in Lebanon as it was traveling to an outpost isolated by ongoing hostilities between Israeli forces and Hezbollah, according to UN officials.

In a statement, Security Council members denounced the assault “in the strongest terms” and reaffirmed their full support for UNIFIL operations in the region. The council did not assign responsibility, though France has blamed Hezbollah for the attack.

The incident occurred on Saturday amid heightened tensions along the Lebanon-Israel border, where clashes have intensified in recent weeks. UNIFIL peacekeepers are mandated to monitor hostilities and support stability in southern Lebanon.

French authorities have not released further operational details about the ambush, while the United Nations has called for accountability and the protection of peacekeeping personnel under international law.

The attack underscores growing risks faced by UN forces operating in volatile regions conflict zones, as diplomatic efforts continue to prevent further escalation in Lebanon.