Ukraine’s president Volodymyr Zelenskyy has said that as many as 10,000 people may have been killed in Mariupol.
The Mayor of the besieged city said the number of dead may be twice that.
The Ukrainians say what has happened here is a war crime. Tonight, we bring you testimony of those who escaped, in a report that contains distressing details
We begin with Sergei, who was inside the Mariupol theatre with his family the day it was bombed.
Produced by Liz Cookman and filmed by Emre Cayluk