Rebel officials said five people were killed and nine wounded at the scene of the attack. City officials said in a statement that three people had been killed in shelling overnight.
Ukrainian President Petro Poroshenko posted a statement on his website saying he had made an impromptu visit to the war-torn region early today.
He stopped in the city of Kramatorsk, 30 miles from the nearest front line, where Kiev says 16 people were killed and 48 wounded in a rocket strike yesterday.
“We demand an unconditional peace,” Mr Poroshenko said.
“We demand a ceasefire, a withdrawal of all foreign troops, and closing of the border.
“We will find a compromise within the country.”
Officials in Kiev also said that 19 troops had been killed and 78 wounded in a day of fighting in Debaltseve, a hotly contested transport hub in the region.
Mr Poroshenko will meet Russian President Vladimir Putin later for peace talks in Minsk, Belarus. France and Germany, who are brokering the talks, have called on the warring parties to refrain from hostilities that could derail the four-way summit.
French foreign minister Laurent Fabius said “quite a number of problems remain” in negotiations aimed at ending the fighting.
He added that it was “very probable” but not certain that French President Francois Hollande would attend the talks.
He said that difficulties remain on the future of embattled eastern Ukraine, guarantees about the Ukraine-Russia border near the area, and the prospects of a possible ceasefire, weapons pullback and prisoner exchange.
Mr Fabius said the aim of the talks is to win an accord, but “not just one on paper”.
Ahead of the latest summit, representatives of the separatists, Russia, Ukraine and the Organisation for Security and Cooperation in Europe met for talks in Minsk.