Kiev (Ukraine) - (AFP) - Kiev called on Sunday for a truce in Mariupopol on the occasion of the Orthodox Easter, which is celebrated by both Russia and Ukraine, at a time when battles are raging in the east and south of the country.

Kiev accused Moscow of "continuously" attacking the Azovstal steel plant in besieged Mariupol, and demanded special negotiations with Russia to release its stranded soldiers.

"Russia is constantly attacking the Azovstal (factory) in Mariupol. The place where our civilians and our army are located is being bombed heavily by air and artillery," Ukrainian presidential advisor Mykhailo Podolyak said on Twitter.

While Russian President Vladimir Putin ordered his forces this week not to attack the factory but to besiege it, Podolyak said Russia was massing its forces in preparation for an "attack".

He said that "the Russian Federation should think about what is left of its reputation."

He called on Moscow to "declare a real truce on the occasion of Easter in Mariupol" and to establish "immediately a humanitarian corridor for civilians."

He also called on Moscow "to agree to a special round of negotiations so that we can transfer or exchange our military."

Ukraine reported a day earlier that Russian forces had "thwarted" an attempt to evacuate civilians from Mariupol.

Fighting erupted in other parts of the country on Sunday, blowing any hopes of a ceasefire for Easter.

The governor of the Donetsk region, Pavlo Kirilenko, said two girls, aged five and 14, were killed in a village in the east by Russian forces.

Pope Francis also called on Sunday for a truce in Ukraine for Orthodox Easter "to ease the suffering of weary people".