Amnesty International is accusing Russia of committing war crimes in the Ukrainian port city of Mariupol.

The human rights organization will soon release an in-depth report on the devastation caused by Russia’s assault on the city on the Sea of Azov, Amnesty’s Secretary-General Agnes Callamard said in a press conference in Johannesburg.

“The siege of Mariupol, the denial of humanitarian evacuation and humanitarian escape for the population, and the targeting of civilians, according to Amnesty International’s investigation, amounts to war crimes,” said Callamard. “That is the reality of Ukraine right now.”

Callamard said “the crisis in Ukraine right now, the invasion ... is not just any kind of violation of international law. It is an aggression. It is a violation of the U.N. charter of the kind that we saw when the U.S. invaded Iraq.”