ZAPORIZHZHIA, Ukraine (AFP) - The UN said on Tuesday (May 3) that 101 civilians had been "successfully evacuated" from the tunnels of the Azovstal plant in Ukraine's battered city of Mariupol, in a joint operation with the Red Cross.

"I am pleased and relieved to confirm that 101 civilians have successfully been evacuated from the Azovstal steel plant in Mariupol," Osnat Lubrani, the UN's Ukraine humanitarian coordinator said in statement.

The evacuation lasted five days and "101 women, men, children and older persons could finally leave the bunkers below the Azovstal steelworks and see the daylight after two months", she added.

Ukrainian civilians and soldiers have for weeks been trapped in the huge steel plant of the Black Sea port, besieged and pummelled by Russian forces since the start of their invasion.

The evacuees were brought to the central city of Zaporizhzhia, which is under Ukrainian control.

The evacuation was agreed after UN Secretary General Antonio Guterres visited Moscow and Kyiv.

Lubrani warned there "may be more civilians who remain trapped" and said the UN was ready to return to the besieged plant to bring them to safety.

Another 58 people joined the evacuation convoy from the city of Mangush, outside Mariupol, she added.

The Red Cross also confirmed the successful evacuation in a separate statement.

It said some of the evacuated civilians were wounded.

The group said it had "hoped that more people would have been able to join", saying more evacuations were "urgently" required.

While it said it was an "immense relief" that the 101 civilians were out of the plant, "the Red Cross has not forgotten the people who are still there".

It vowed not to "spare any effort to reach them".