Fighting surged in east Ukraine on Wednesday as Kiev accused pro-Russian forces of launching a "large-scale" attack in breach of a tenuous ceasefire.

Fighting surged in east Ukraine on Wednesday as Kiev accused pro-Russian forces of launching a "large-scale" attack in breach of a tenuous ceasefire.

Rebels claimed that 15 separatist fighters and civilians were killed as fresh clashes flared, but denied that they had started a new assault.  

Medics on the government side told AFP that one civilian had died and five more were wounded. Ukraine's defense minister said seven government troops were injured.

The fighting -- some of the most serious since a shaky European-brokered ceasefire was signed in Minsk in February -- has revived Kiev's fears that the rebels may be readying for an all-out attack.