A unilateral ceasefire called for by Kiev is under pressure after pro-Russian separatists attacked an Ukrainian military base and posts on the border with Russia, government forces said.
The fresh attack came just hours after the start of a ceasefire at 10 p.m. on Friday by Ukrainian forces, ordered by President Petro Poroshenko as part of his plan to end the rebel insurgency in the east of the country.
More top news
Jeremy Corbyn's economic policies would harm the poor and leave the Tories in power for a decade, Chris Leslie has warned.
Landlords have been warned they could face up to five years in prison if they fail to remove illegal immigrants from properties.
A picture of Cecil the lion - the animal killed by an American dentist in Zimbabwe - has been projected on to the Empire State Building.