Ukraine's military says pro-Russian separatists have shot down a Ukrainian military jet.
Military spokesman Vladislav Seleznyov said the plane crashed some 40 kilometers northeast of the city of Donetsk, the main stronghold for separatists.
He said the pilot had ejected safely after he managed to steer the plane away from a residential area. A search-and-rescue mission is currently under way for the pilot.
The Ukrainian military has lost a string of aircraft during four months of fighting against pro-Russian rebels in the east.
Last month, a Malaysian airliner was shot down over rebel-held territory, allegedly by the separatists, killing 298 people.
The head of the Ukrainian Security Service (SBU), Valentin Nalivaychenko, on August 7 said the separatists had wanted to bring down a Russian airliner to create a pretext for a Russian invastion.