A large rally was held in Kyiv, Ukraine, on Sunday to denounce Russia for allegedly killing Ukrainian prisoners of war and to call for the release of others who remain captive.

The event marked the second anniversary of the July 28, 2022, attack on an Olenivka prison in the eastern region of Donetsk. Over 50 Ukrainians are said to have been killed in the attack. Ukraine and Russia blame each other for the incident.

On Sunday, many people gathered in central Kyiv, calling Russia a terrorist country and appealing for the release of Ukrainian soldiers and other captives.

Drivers honked their horns in a show of support.

A 29-year-old rally participant said they gathered to remind the world of the horrendous war crime. She said Ukraine has to reclaim the people who defended the country.

This month, the Ukrainian government announced that there have been over 50 prisoner exchanges with Russia, resulting in the release of about 3,400 people.

But many Ukrainians are believed to still remain captive.