Mortar fire rocks rebel stronghold in east Ukraine

DONETSK Ukraine (Reuters) - Mortar fire rocked the southern reaches of the separatist stronghold of Donetsk overnight, despite efforts to secure a ceasefire in eastern Ukraine, witnesses said on Thursday.

Northern areas of the city also came under fire on Wednesday after Russian President Vladimir Putin proposed a seven-step plan for peace following a telephone conversation with Ukrainian President Petro Poroshenko.

There were unconfirmed reports of deaths in Petrovka to the south of Donetsk.

"I don't think the Ukrainians can hold on to any peace agreement. They talked peace yesterday and then shell the Petrovka district of the city overnight. Civilians were killed again," said a rebel fighter, who used the nom de guerre Miner.

(Reporting by Gabriela Baczynska, Writing by Thomas Grove, Editing by Timothy Heritage)