A video was posted on social media showing men who appear to be wounded North Korean soldiers receiving medical treatment at a hospital in Russia’s Kursk region.

The Ukrainian online outlet Strana.ua posted the video on Telegram, claiming that more than 100 North Korean soldiers are under treatment at the Kursk hospital after fighting alongside Russian forces.

While it is difficult to verify whether the men in the video are in fact North Korean soldiers, the Ukrainian military’s Center for Countering Disinformation claimed on Telegram that there are over 150 injured North Korean soldiers at the hospital.

A U.S. official, meanwhile, confirmed on Wednesday that there have been hundreds of North Korean casualties in the combat operation in Kursk.

In the Russian capital, Moscow, Lt. Gen. Igor Kirillov, chief of Russia’s nuclear, biological and chemical protection forces, was killed outside an apartment building along with his assistant when a bomb hidden in an electric scooter went off.

While Ukraine has accused Kirillov of being responsible for the use of chemical weapons against Ukrainian troops, foreign media outlets say Ukraine’s security service carried out the assassination.

Dmitry Medvedev, deputy chair of Russia’s Security Council, accused the military and political leadership of Ukraine of masterminding the assassination, while Moscow’s foreign ministry said the West, including the U.S., approved the attack.