By Pavel Polityuk

LVIV, Ukraine (Reuters) -A convoy of at least 160 cars left Mariupol on Monday in the first successful attempt to arrange a humanitarian corridor out of the encircled Ukrainian city after over a week of trying.

Civilians have been trapped in the southern port city by Russian shelling for more than two weeks and have been without heating, electricity and running water for most of this time, the Ukrainian authorities say.

More than 2,500 residents have been killed there since the Russian invasion on Feb. 24, a Ukrainian official said.

A local ceasefire arranged with the Russian forces besieging Mariupol held long enough for the first cars to leave for the city of Zaporizhzhia about 225 km (140 miles) away, senior Ukrainian and local officials said.

Efforts were also being made to deliver supplies to the remaining civilians after the city council said on Sunday the last reserves of food and water were running out. Russia says it does not target civilians.

"At one o'clock (1100 GMT) the Russians opened a checkpoint and those who have cars and fuel began to leave Mariupol in the direction of Zaporizhzhia," Andrei Rempel, a representative of the city council who is now in Zaporizhzhia, told Reuters.

"In the first two hours, 160 cars left. There are probably already many more now. The city continues to be bombed but this road is not being shelled. We don't know when the first cars can get to Zaporizhzhia as there are still many Russian checkpoints that need to be passed."

The city council said the convoy had already passed Berdyansk, a city about 85 km from Mariupol.

Reuters was unable to verify the convoy's progress from Mariupol, a city of about 400,000 in peacetime that local officials say has been devastated by Russian shelling.

'CRITICAL' SITUATION

The city council described the situation in Mariupol on Friday as "critical".

Presidential adviser Oleksiy Arestovych said on Monday that more than 2,500 residents had been killed since Feb. 24. The toll could not be independently verified by Reuters.

(editor：)