Ukraine evacuated 50 civilians from the Azovstal plant in the besieged city of Mariupol, Ukrainian Deputy Prime Minister Iryna Vereshchuk said on Friday.

"The evacuation was extremely slow. However, today we managed to free 50 women, children and the elderly from Azovstal," Vereshchuk wrote on Facebook.

The evacuation will continue on Saturday morning, Vereshchuk said.

Earlier in the day, Ukraine's Presidential Office head Andriy Yermak said that Ukraine had evacuated about 500 civilians from Mariupol.

Mariupol, a key Azov Sea port city in eastern Ukraine, saw one of the worst bouts of violence in the Russia-Ukraine conflict.