KIEV, July 16 - Pro-Moscow separatists battled to break through lines of government forces near the border with Russia in eastern Ukraine on Wednesday, and a tentative step towards agreeing a ceasefire in the intensifying three-month conflict failed, Reuters reported.

Fighting has escalated sharply since Ukrainian forces pushed rebels out of their stronghold in the town of Slovyansk 10 days ago. The past several days have seen Russia and Ukraine trade accusations of firing across the border.

Ukraine's military said 11 more troops were killed in the space of 24 hours, mostly in clashes near the frontier.