37 Dead as Ukraine Fighting Intensifies ahead of Peace Summit

As diplomats scrambled to finalize a deal to end the 10-month war, pro-Russia rebels sought to encircle railway hub Debaltseve and Ukrainian forces launched a counter-offensive around the strategic port of Mariupol.

Ukrainian President Petro Poroshenko said rockets for the first time hit the military's command center in Kramatorsk, the government's administrative capital in the region, well behind the frontlines and far from rebel positions.

The strikes also hit residential areas around the city, killing 15 local residents, officials said. At least 63 people, including five children, were also wounded, according to AFP.

Kiev and the West accuse Moscow of supplying and training the heavily armed separatists, but Russia denies the claims.

Rebels say their weapons have been captured from Ukrainian forces, although Kiev has cited numerous cases of the insurgents using advanced weapons that are only available from Russian arsenals.

"The shelling is with Vladimir Putin's compliments, who else could have done this?" shouted a Kramatorsk resident as he walked past an unexploded rocket.

Another seven Ukrainian soldiers and eight civilians were killed in fighting over the last 24 hours, Kiev officials and rebels said, including in Debaltseve, which the insurgents claim to have surrounded.

Rebels, who rarely give a military toll, said that seven of their fighters had been killed.

Ukrainian forces took control of three villages east of Mariupol, around 90 kilometers (60 miles) south of the rebel stronghold Donetsk, and fierce fighting raged for control of two more, senior interior ministry adviser Zoryan Shkiryak said.

The violence came as rebels, diplomats and mediators from the Organization for Security and Cooperation in Europe (OSCE) went into talks in the Belarussian capital Minsk to bridge gaps on a possible peace deal.

The leaders of Ukraine, Russia, France and Germany hope to sign the deal at a summit in the city on Wednesday, but German Foreign Minister Frank-Walter Steinmeier warned all parties against acts of "sabotage".

"It wouldn't be the first time that an act of political sabotage, a targeted strike, destroys all hopes of a ceasefire," he said.

"That's why I hope that no party to the fighting pushes things to the point where an explosion of violence calls Minsk into question."