KIEV/DONETSK (Reuters) - Six Ukrainian soldiers were killed in the past 24 hours, a military spokesman said on Saturday, as a fragile ceasefire in the east was tested by heavy mortar fire in the separatist stronghold of Donetsk ahead of a rebel election.
The deaths follow the killing of seven Ukrainian servicemen on Thursday, as tension grows in the run-up to Sunday's election for a separatist leadership that has been denounced as illegal by Kiev and criticized as illegitimate by the West.
"In the past 24 hours our casualties included six killed and 10 wounded," spokesman Volodymyr Polyovy said at a televised briefing.
Sustained gunfire and artillery bombings could be heard from the center of Donetsk, according to a Reuters witness.
"The fight is still going on over the airport," said a rebel commander in the city center dressed in camouflage and carrying an automatic rifle.
Despite sporadic violence at the airport, a strategic point that both Ukrainian troops and rebels lay claim to in part, previous weeks had been relatively quiet since a Sept. 5 ceasefire.
(Reporting by Pavel Polityuk in Kiev and Thomas Grove in Donetsk; Writing by Alessandra Prentice; Editing by Stephen Powell)