Kiev - Fighting raged in eastern Ukraine on Sunday as pro-Russian separatists used artillery fire to try to dislodge government forces from a strategic rail hub after peace talks collapsed.
Hopes of easing the situation evaporated on Saturday with Ukraine's representative and separatist envoys accusing each other of sabotaging negotiations.
"Fighting continues across all sections of the frontline," Kiev military spokesperson Volodymyr Polyovy said in a briefing, noting that 13 soldiers had been killed in the past 24 hours. Other Ukrainian authorities said at least 13 civilians had also been killed in attacks.
Ready for dialogue
The Organisation for Security and Co-operation in Europe (OSCE), which took part in the talks in Minsk, Belarus, along with envoys from Ukraine and Russia, said rebel delegates had not been ready to discuss crucial points of a peace plan.
"In fact, they were not even prepared to discuss implementation of a ceasefire and withdrawal of heavy weapons," the OSCE said in a statement.
It said rebels had instead pushed for a revision of a ceasefire plan agreed in Minsk in September last year.
The terms of that 12-point protocol have been repeatedly violated but Kiev and foreign governments see it as the only viable road map to end the nine-month-long conflict in which more than 5 000 people have been killed.
Rebel strongholds
The rebels rejected the OSCE's assessment, saying they were ready for dialogue, but unwilling to accept an "ultimatum" from Kiev as long as government forces continued shelling civilian areas, separatist news service DAN quoted rebel envoy Denis Pushilin as saying.
Ukraine's President Petro Poroshenko held a three-way phone conversation with German and French leaders Angela Merkel and Francois Hollande in which they expressed their disappointment, German government spokesperson Steffen Seibert said.
"The separatists are urged not to block the talks. Russia must, in this regard, also influence the rebels," he said.