Ukraine is marking four years since the liberation of Bucha, north of Kyiv, where Russian forces committed some of the worst atrocities of the war.

Hundreds of civilians were found massacred across the city, although Russia continues to deny responsibility.

Oleksandra Matviichuk, a human rights lawyer and head of the Ukrainian non-profit organization Center for Civil Liberties, which won the Nobel Peace Prize in 2022, tells DW that she was "shocked" by what she and her team discovered in Bucha after the retreat of the Russian army.