A small commercial plane with 18 people aboard crashed Thursday in the thickly forested mountains of Indonesia's North Sumatra province, authorities said. There were no survivors.

The crash site of Nusantara Buana Air's Casa 212 was found in the Bahorok forest, Langkat regency, North Sumatra Air Communications Agency head Ali Turki Siregar told the state-run news agency Antara.

Rescue workers dispatched to the scene were struggling to reach the wreckage due to the rugged terrain and heavy rains.
The plane was halfway through its 30-minute flight between Medan, North Sumatra, and Kutacane, Aceh province, when it lost communication, Transportation Ministry spokesman Bambang Ervan told the Associated Press.

The turbo-prop plane made a distress signal before finally disappearing from the radar, Bonar Hutagaol, an Air Force marshal, told TVOne.

Witnesses saw the plane smoking and circling low before the crash.

The Casa 212 is a Spanish-designed plane built in Indonesia in 1989. Its last double inspection before takeoff was last week and showed that it was in good condition, airline spokesman Robur Rizallianto told the AP.

Plane crashes are rare in Indonesia, although air transport is a major mode of traveling between islands.