MOSCOW (AP) — Russia's aviation agency says 19 people have died after a helicopter carrying oil workers crashed.

The Federal Air Transport Agency says in its statement Saturday that 16 of the 19 passengers on board and all three crew members died in Friday's crash in northern Russia.

The Mi-8 helicopter was traveling from Vankor to Staryi Urengoi in the Yamalo-Nenets region when it crashed about 45 kilometers (28 miles) northeast of Staryi Urengoi.

Rescuers found the helicopter lying on its side in the tundra. The agency said poor visibility and strong winds could have been factors.

The Mi-8 has been a mainstay of Soviet and Russian aviation since the late 1960s and is widely used worldwide.