More than 3,000 civilians of Mariupol are being held by Russian occupiers in a "filtration prison" – former correctional colony No. 52 in the village of Olenivka, Donetsk region, said the Verkhovna Rada Commissioner for Human Rights Liudmyla Denisova.

"There are about 30 volunteers among the hostages who tried to bring humanitarian aid to Mariupol and rescue residents. Before being sent to the colony, the occupiers subject the detained citizens to many hours of interrogation and torture with the use of electric current. The term of ‘filtration’ means staying in the colony for 30 days. For the ‘especially unreliable’ – activists, former military, law enforcement officers, it continues for another month," she wrote on Facebook.

The Ombudsman stressed that hostage-taking and torture is an act of terrorism in accordance with the Council of Europe Convention on the Prevention of Terrorism and a war crime in accordance with article 8 of the Rome Statute of the International Criminal Court.

"I appeal to the UN Commission to Investigate Human Rights Violations during the Russian military invasion of Ukraine to take into account these facts of war crimes and violations of human rights of the Russian Federation in Ukraine. I call on the international community to recognize the Russian Federation as a state that supports and carries out terrorism!" she urged.