Taipei  - A rescue helicopter sent by Taiwan's Air Force to ship supplies to a mountain village crashed in the southern county of Pingtung Tuesday, the rescue unit said.

Three people, including the pilot, co-pilot and a crew member, were unaccounted for after the crash, the unit leader said.

"The helicopter apparently hit the mountain before plunging into the Yila River valley," said the leader of the Pingtung rescue unit.

Helicopter UH1H 502 was carrying water and food supplies for 600 people trapped in a mountain village in Wutai.

The Air Force lost contact with the aircraft when it flew between Santimen and Wutai in Pingtung County at 3:30 pm (0730 GMT), a spokesman for the Air Force said.

The cause of the crash was not immediately known, he said.

The helicopter was on its second mission to deliver supplies to the villagers, he said.

The Air Force sent another helicopter to look for possible survivors, while the Pintung rescue unit organized a 30-member team to join in the search, he said.

The mountain village was cut off by a mudslide caused by Typhoon Morakot, which caused serious damage when it slammed into Taiwan on Friday, leaving 41 dead, 62 missing and 35 injured. (dpa)