Kiev (AFP) - The Ukrainian military said Saturday its forces had repelled an insurgent attack on the airport in the eastern separatist stronghold of Donetsk, despite an eight-day ceasefire.

"Many rebels backed by six tanks launched an assault against the airport on Friday which was heroically repelled by the soldiers," the press service for the military operation in eastern Ukraine said.

While pro-Russian separatists have held the city of Donetsk itself for months Ukrainian forces have dug in at the airport since a major battle there in May.

Although the fighting in eastern Ukraine has diminished since the truce agreement was signed by Kiev, Moscow and the rebels on September 5, there have been numerous reports of shelling around Donetsk airport.

"Are Russian forces trying to capture Donetsk airport?" Swedish Foreign Minister Carl Bilt said on Twitter on Saturday. "If that is the case then it's a clear Moscow violation of ceasefire agreement."