With Russia stepping up its attacks on eastern Ukraine, attention is now focused on humanitarian attempts to help people evacuate from the besieged city of Mariupol.

The Russian defense ministry reports that fierce battles are taking place in the eastern region of Donetsk. It says Ukrainian military airfields and a refinery have been destroyed.

A woman who survived last month's attack on a Mariupol theater with her two small children describes the horror.

She said, " I was blown off my feet and my daughter was buried under debris. It was a miracle we survived. Those who were on the stage of the theater all died."

More than 300 people who had sought shelter in the building were killed in the blast.

Meanwhile, more than 50 churches and historical sites around the country have been hit by missiles and artillery fire.

UNESCO says the second largest city of Kharkiv was targeted by heavy Russian attacks.

Ceasefire talks between Russia and Ukraine resumed online on Friday but no significant progress has been reported.