Pro-Moscow rebels and government officials said today that seven civilians were killed across the conflict zone during the past 24 hours while Ukraine's military said eight soldiers lost their lives.
The unrest came as Europe warned Russia it risked fresh sanctions if the fighting did not stop.
The rebels and Kiev agreed a peace plan yesterday after marathon talks in the Belarussian capital Minsk between the leaders of Russia, Ukraine, France and Germany.
A ceasefire across the conflict zone is meant to start at midnight Ukraine time Sunday (2200 GMT Saturday) with both sides supposed to begin pulling back heavy weaponry from along the frontline no later than two days after that.
The fragile agreement is seen as the best hope of ending the conflict, which has killed at least 5,480 people and ratcheted East-West tensions to highs not seen since the Cold War, but skepticism remains high after the collapse of a similar previous peace plan.
Kiev and the West accuse Russia of stoking the war in ex-Soviet Ukraine by pouring arms and troops to help the pro-Russian rebels fighting Kiev government troops in Ukraine's industrial east. Moscow denies the charges.
Speaking late yesterday after a European Union summit in Brussels, German Chancellor Angela Merkel warned Russia that the bloc, which has already slapped Moscow with sanctions over
the crisis, was not ruling out further measures if the truce failed.
"If it works well we would be very happy to go with the agreement. If there are difficulties we wouldn't rule out other sanctions," she said.
French President Francois Hollande, who along with Merkel attended the 17-hour talks in Minsk that also included Russian President Vladimir Putin and Ukrainian President Petro Poroshenko, agreed.
If the truce was not respected, "we would return to a process... of sanctions that would be in addition to those already in place."

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