Lethal shelling continued to rock towns in war-torn eastern Ukraine late Saturday, in the hours before a Sunday cease-fire began.
Seven Ukrainian troops were killed and 23 wounded in attacks by pro-Russia separatists, according to Ukrainian National Defense and Security Council spokesman Andriy Lysenko. Twelve separatist fighters died and 40 were wounded, one of their military commanders said.
In marathon negotiations in Minsk, the capital of Belarus, leaders of Germany, France, Russia and Ukraine worked out an agreement Thursday that would halt fighting at 12:01 a.m. Sunday in eastern Ukraine. But in the hours leading up to the cease-fire, at least two towns were ravaged by shelling.
"The towns of Debaltseve and Shirokino are significantly destroyed and many houses in them are on fire," Maj. Gen. Alexander Rozmaznin, Ukraine's envoy to the joint cease-fire monitoring commission, said in an interview. "Thank God most civilian residents have been already evacuated from those places."
"All through the day the separatists were desperately trying to gain control over more territory before the cease-fire, but to no avail," Rozmaznin said.
A bombardment of the industrial city of Donetsk on Saturday left three civilians dead and 12 wounded, Eduard Basurin, chief political officer of the self-proclaimed Donetsk People's Republic armed forces, said in an interview.
"We will certainly abide by the cease-fire agreement, but we have strict orders to respond with fire as soon as we are attacked," Basurin said.
"We have no reason at all" to trust government forces after the cease-fire begins, he said. "But we will not be the first to shoot."
Basurin said separatist forces lost three tanks, two armored vehicles and three military trucks in fighting Saturday, but destroyed six tanks, three armored vehicles and 22 artillery units of the Ukrainian security forces. Separatists took 60 Ukrainian government troops prisoner, Basurin said, a claim not confirmed by the government.
Ukrainian President Petro Poroshenko said that regardless of the agreement, Ukraine was dealing with "a crafty and cynical enemy," and he threatened a resolute response should the cease-fire be violated by the other side.
"We count that common sense prevails over sick imperial ambitions" on the part of Russia, Poroshenko said in a statement Saturday. "If there is no peace, I will immediately submit a martial law provision to [parliament] ... that would allow us to more reliably and efficiently mobilize ourselves, concentrate efforts and protect our land."
During the day, Poroshenko spoke by phone with President Obama, and they agreed "to further coordinate efforts should the conflict escalate," the statement said. Poroshenko also spoke with French President Francois Hollande and German Chancellor Angela Merkel, who had met with him and Russian President Vladimir Putin during the negotiations in Belarus.
U.S. Ambassador to Ukraine Geoffrey Pyatt posted an aerial map of the Debaltseve area on his Twitter account showing what he said he believed were at least five positions of Russian army artillery in eastern Ukraine.
"We are confident these are Russian military — not separatist — systems," the ambassador wrote.
The Russian Foreign Ministry in response accused the United States and a number of Western powers of siding with "radical nationalists" in Ukraine's parliament and distorting components of the Minsk accords."
More than 5,350 people have been killed, thousands wounded and more than a million displaced in 10 months of fighting, the United Nations reported this month.