Looking for His glorious appearing! Titus 2:13

Government forces used aircraft, helicopters and artillery in a fierce attack to try to root out the separatists who have controlled Slaviansk and surrounding areas since early April.

But the rebels on Wednesday denied the government's casualty figures. "Reports of 300 dead are not true. Losses to the Ukrainian side were more than ours," Aleksander Boroday, "prime minister" of the self-proclaimed Donetsk People's Republic, was quoted as saying by Interfax news agency.

Describing the fighting as "heavy", the government forces spokesman, Vladyslav Seleznyov, said two servicemen had been killed and 45 wounded.

Fighting was continuing in Slaviansk region and mopping-up operations were underway in the nearby town of Krasny Liman, which he said government forces had taken control of on Tuesday.

President-elect Petro Poroshenko ordered the resumption of operations by government forces to quell the rebellion by pro-Russian militia in the Russian-speaking east soon after scoring a resounding victory in an election on May 25.

The Kiev government says the fighting is being stirred up by Moscow, which opposes its pro-Western course. Kiev also accuses Russia of letting volunteer fighters cross into Ukraine to fight alongside the rebels. Moscow denies this and is urging Ukraine to end military operations and open dialogue with the separatists.

Since government forces resumed their push against the rebels, there have been clashes in and around the main industrial hub of Donetsk and near the border town of Luhansk, with loss of life on both sides.