KYIV, Ukraine — A series of strikes across Ukraine, Russian-occupied territories, and within Russia itself have resulted in the deaths of at least 16 individuals, officials reported. These attacks coincided with the 40th anniversary of the Chernobyl nuclear disaster, heightening concerns about the potential risks of military actions near the nuclear plant amidst Russia’s prolonged invasion of Ukraine.

In the city of Dnipro, the toll from Russian drone and missile strikes has climbed to nine, as confirmed by regional leader Oleksandr Hanzha on Sunday.

In Russian-occupied Crimea, specifically in the port city of Sevastopol, a Ukrainian drone strike claimed the life of one man, according to authorities appointed by Moscow. Russia annexed Crimea from Ukraine in 2014, a move largely condemned as illegal by the international community, and has since used the region as a strategic base during the ongoing conflict.

Leonid Pasechnik, the Moscow-appointed governor in Ukraine’s Luhansk region, stated that three people died in an overnight drone attack by Ukraine on a local village, following the deaths of two individuals on Saturday morning. Russia recently claimed full control over Luhansk, a statement Ukraine disputes.

Ukraine has not publicly responded to these incidents, and the Associated Press has been unable to independently verify these claims.

Additionally, local authorities reported that a Ukrainian drone strike on Russia’s Belgorod border region resulted in the death of a woman, marking another fatality in the ongoing conflict.

Ukrainian forces also struck an oil refinery in Yaroslavl, deep inside Russian territory, Ukraine’s General Staff said Sunday. The strikes sparked fires at the facility, which processes 15 million tons of oil a year and produces gasoline, diesel and jet fuel for the Russian military. Russia did not immediately comment.

Ukraine has developed its own long-range drones, which can reach targets some 900 miles inside Russia. It has used them recently against Russian oil facilities as Moscow looks to boost its exports after the Trump administration gave it a temporary waiver from sanctions to ease supply constraints. Kyiv officials complain that Russia will use the additional revenue on new weapons to hit Ukraine harder.

Ukraine’s President Volodymyr Zelensky marked the anniversary of the Chernobyl nuclear disaster to warn that Russian attacks risk repeating history.

“Through its war, Russia is once again bringing the world to the brink of a man-made disaster — Russian-Iranian Shaheds regularly fly over the plant, and one of them struck the confinement last year,” he wrote on Facebook.

“The world must not allow this nuclear terrorism to continue, and the best way is to force Russia to stop its reckless attacks,” he said.

Rafael Grossi, director general of the International Atomic Energy Agency, echoed those concerns during a visit to Kyiv, saying repairs to the plant’s damaged outer protective shell must begin immediately. IAEA assessments show the damage sustained after a strike last year has already compromised a key safety function of the structure, he said, warning that years of inaction could heighten danger to the original sarcophagus beneath it. The European Bank for Reconstruction and Development said repairs would require at least 500 million euros ($586 million).

Ukrainian officials say a Russian drone struck the outer shell of the plant’s New Safe Confinement structure — a $2.1 billion archlike enclosure completed in 2019 over the remains of Reactor No. 4 — in February 2025. Moscow denied targeting the plant, alleging Kyiv staged the attack.

Russia’s Defense Minister Andrei Belousov visited North Korea on Sunday for talks with North Korean leader Kim Jong Un about future military cooperation between the countries.

Belousov said the countries agreed to “transition military cooperation to a sustainable, long-term basis,” according to Russia state news agency Ria Novosti.

During the visit, he presented the Russian Order of Courage to Korean service members who served in Russia’s Kursk region, where Ukraine launched a surprise incursion in August 2024.

Kim has sent thousands of troops and large weapons shipments to support Russia’s war against Ukraine.