STORY: Michelle Bachelet, addressing the U.N. Human Rights Council in Geneva, said the death toll is likely “thousands higher”.
She also said that nine out of 10 residential buildings and six out of 10 private houses have been damaged or destroyed.
“These deaths were caused by air strikes, tank and artillery shelling, and small arms and light weapons during street fighting," she said.
Bachelet also raised concern over the “filtration” process in the city where arbitrary determinations, intimidation and humiliation, which may amount to ill-treatment, have been reported.
Russia seized full control of Mariupol last month when more than 2,400 Ukrainian fighters surrendered at the besieged Azovstal steelworks.
Moscow's capture of Mariupol helped it secure full control of the Sea of Azov coast and create a land bridge linking mainland Russia to Crimea, which it annexed from Ukraine in 2014.
Ukrainian President Volodymyr Zelenskiy has described Mariupol as "completely destroyed," but Moscow has pledged to rebuild it.