KIEV - Insurgents brought down a Ukrainian military helicopter near the rebel-held eastern town of Slavyansk, killing 14 troops onboard, acting President Alexandr Turchynov said Thursday.

Insurgents attacked a helicopter, which was carrying troops for a change of duty, with a shoulder-fired anti-aircraft missile, Turchynov told parliament.

Ukrainian major-general Sergei Kulchitskii was among those killed, he said.

Earlier in the day, Ministry of Internal Affairs adviser Anton Gerashchenko said a military helicopter, which was delivering food and ammunition to Ukrainian troops, went down near Slavyansk, but there was no immediate word on the casualties in the incident. It is unclear if he was referring to the same incident as Turchynov.

Heavy fighting between Ukrainian government forces and rebels seeking independence from Kiev has been raging in Slavyansk for weeks. Ukraine launched an "anti-terrorist" operation in the eastern city in early April following the seizure of several administrative buildings and the murder of civilians who supported a united Ukraine.

Maj-Gen. Kulchitskii was an active participant and one of the commanders of the government's "anti-terror" actions.

The 51-year-old officer served as the head of the Interior Ministry's combat training department.