Vadym Boychenko, the mayor of the besieged city of Mariupol, said a new mass grave had been identified 10 kilometers (6 miles) north of the city.

Several victims were located there, though authorities are trying to identify how many victims are in the unmarked graves.

Over the past several days, satellite photos have shown what appear to be images of mass graves on the outskirts of the city.

Mariupol has been under siege for two months, with 100,000 civilians remaining trapped in the city. The remaining Ukrainian forces in the city are holding out in a sprawling steel factory. Ukrainian officials have been trying for weeks to secure the safe evacuation of civilians.

Should Russian forces succeed in completely capturing Mariupol, they will have a land corridor to Crimea, which Russia seized in 2014.