Story highlights

NEW: State media: Provincial governor says poor weather, not terror attack, is to blame

17 military personnel died in the helicopter crash, state media say

The incident occurred in Turkey's southeastern Siirt province

The helicopter is thought to have crashed into a mountainside in fog

Istanbul CNN  — 

Seventeen military personnel died in a helicopter crash in Turkey, state media reported Saturday.

The Sikorsky-type helicopter, which was carrying soldiers to an operation, crashed in Pervari district, in Turkey’s southeastern Siirt province, official broadcaster TRT said.

The military helicopter is believed to have plowed into a mountain because of fog, the broadcaster said.

Four of those killed were crew members, the other 13 soldiers, the semi-official Anadolu Agency cited Siirt governor Ahmet Aydin as saying.

The governor stressed that the crash was caused by poor weather conditions, not a terrorist attack, the news agency said.

Turkey’s military has been combating a long-running insurgency by Kurdish militants in the southeast of the country.

The conflict has claimed more than 30,000 lives over the past three decades.

CNN’s Gul Tuysuz contributed to this report.