Ukrainian officials on Sunday accused Russian forces of killing surrendering Ukrainian soldiers, a war crime if confirmed, after grainy images on social media appeared to show two uniformed men being shot at point-blank range after leaving a trench.

The video shows the soldiers, one of them with his hands raised, leaving at gunpoint and lying on the ground before a group of Russian soldiers appear to open fire. It was not immediately possible to verify the authenticity of the video or the circumstances under which it was recorded.

Ukraine’s Prosecutor General’s Office launched a criminal investigation on Sunday, hours after the Ukrainian military’s press office said in a statement that the images are genuine.

“The video shows a group in Russian uniforms shooting at point-blank range at two unarmed servicemen in Ukrainian Armed Forces uniforms who were surrendering,” the prosecutor’s office said in a Telegram update on Sunday.

kyiv, its Western allies and international human rights organizations have repeatedly accused Moscow of violating international humanitarian law since it launched its large-scale invasion in February 2022. The Kremlin denies these accusations.

The video first appeared Saturday on DeepState, a popular Ukrainian Telegram channel that reports on the war. The publication claimed that the images came from the front lines near Avdiivka, a Ukrainian stronghold in the partially occupied east of the country, where there has been fierce fighting in recent weeks.

The Prosecutor General’s Office said on Sunday that the incident took place in the Pokrovsk district, which includes Avdiivka and its surroundings.

Via Telegram, Ukraine’s human rights chief Dmytro Lubinets described the incident as “another blatant example of Russia’s violations of international humanitarian law.”

Oleksandr Shtupun, spokesman for the Ukrainian military group fighting near Avdiivka, was quoted by Ukrainian media as saying the video was a “clear confirmation” of Moscow’s lack of respect for the laws of war.

In March, images of a man exclaiming “Glory to Ukraine” before being shot dead in a wooded area sparked national outrage in Ukraine, as senior officials alleged he was an unarmed prisoner of war killed by Russian soldiers.

Last summer, kyiv and Moscow also blamed each other for an artillery attack on a prison in occupied eastern Ukraine that killed dozens of Ukrainian prisoners of war. Both sides claimed that the assault on the Olenivka facility was aimed at covering up atrocities, and Ukrainian officials alleged that captive soldiers were tortured and executed there.

In July, the U.N. human rights chief rejected Moscow’s claim that a rocket attack had caused the explosion.

Also on Sunday, Ukraine’s Energy Ministry reported that nearly 1,000 cities and towns suffered power outages that day, with hundreds of settlements in the west hit by winter weather and others affected by ongoing fighting.