Ukraine says its forces killed 12 rebels at Donetsk airport

Pro-Russian rebels on a tank get ready to take position near the Sergey Prokofiev International Airport during fighting with Ukrainian government forces in the town of Donetsk, eastern Ukraine, October 4, 2014. REUTERS/Shamil Zhumatov

KIEV (Reuters) - Pro-Russian separatists have suffered their worst casualties since a ceasefire officially began on Sept.5, losing 12 men in attacks on buildings at Donetsk airport, Ukrainian military officials said on Saturday.

The ceasefire in eastern Ukraine has become increasingly frayed in recent days, leading to the death of a number of civilians and soldiers as well as a Red Cross worker in the rebel stronghold of Donetsk.