Rescue teams are heading to its last known location near the North Sumatran village of Bahorok.

The CASA C-212 aircraft was flying between North Sumatra and Aceh provinces, transport ministry aviation head Herry Bakti said.

It lost contact with air traffic control after sending out an emergency signal, he said.

"The plane crashed sometime between 7:28 (00:18 GMT) and 8:05 this morning around Bahorok mountain, which is about 36 nautical miles northwest of Medan," the official said.

It was carrying 15 passengers and a three-strong crew.

Indonesia relies heavily on air transport and has a poor aviation record.

In May, 27 people died when an Indonesian passenger plane crashed into the sea off the eastern province of West Papua.