By Kubra Chohan

ANKARA

A rescue helicopter crashed into mountains in eastern Japan, killing all nine crew members aboard, local media reported on Saturday.

The helicopter crashed at prefectural border between Gunma and Nagano while it was checking a mountain trail for climbers, according to the Kyodo news agency..

The cause of the crash remains unknown, though eyewitnesses have said the engine made strange sounds and it was flying at a low altitude.