Dozens of civilians evacuated from Mariupol steel plant

Roughly 100 civilians have been evacuated from a besieged  steel plant in the eastern Ukrainian city of Mariupol, Ukrainian President Volodymyr Zelensky said on Sunday.

The UN said earlier that a "safe passage operation" was going on at the Azovstal plant, the last holdout in the Black Sea port city that has endured a Russian blockade for the full duration of the conflict that began on February 24.

Russia's defence ministry gave a lower figure of 80 civilians, adding: "Those who wished to leave for areas controlled by the Kyiv regime were handed over to UN and ICRC (Red Cross) representatives."

The UN has not said how many civilians it is transporting and it was not immediately clear why the sides had given different figures.

Thousands have been killed and millions displaced since Russia's invasion, and stories of the harsh conditions in besieged Mariupol have horrified the world.

"Evacuation of civilians from Azovstal began," Zelensky said on Twitter, adding that they were due to arrive in Ukraine-controlled Zaporizhzhia on Monday.

"Grateful to our team! Now they, together with the UN, are working on the evacuation of other civilians from the plant."

The Russian defence ministry earlier confirmed civilians were leaving, releasing a video that showed cars and buses travelling in the dark marked with a "Z", the letter used by the Russian forces in the conflict.

On the front line in the east, Russian troops have advanced slowly but steadily in some areas -- helped by massive use of artillery -- but Ukrainian forces have also recaptured some territory in recent days, particularly around the city of Kharkiv.