A small plane crashed into a hillside in Indonesia's easternmost Papua province Thursday, killing all four people on board, police said.

The Avia Star plane was transporting cargo from the provincial capital, Jayapura, to the nearby district of Wamena when it went down, said Maj. Gen. Bagus Ekodanto, the local police chief.

The bodies of the pilot, co-pilot and two other crew members were pulled from the smoldering wreckage, he said.

It's not clear what caused the accident, but a witness told the Antara news agency the plane was seen circling around the hill before tumbling from the sky.

Smoke billowed from the scene.

There are few roads in Papua, which occupies the western half of New Guinea, and air travel is a common form of transport.

It is considered one of the world's most dangerous places to fly. Many areas are mountainous and prone to dangerously low clouds and sudden weather changes.