An Australian navy helicopter crashed on the earthquake-devastated Indonesian island of Nias (search), killing nine people, the defense department said Sunday. Two others were rescued but were seriously injured.

The Sea King (search) helicopter crashed Saturday afternoon near the town of Gunung Sitoli (search), off the west coast of Sumatra, a defense statement said.

The chopper was from an Australian navy transport ship that arrived Saturday from Singapore after a three-month relief mission in Indonesia's tsunami-ravaged province of Aceh.

The two survivors were rescued by a second helicopter from the ship, HMAS Kanimbla, which has a floating hospital, according to the statement.

"They are in a serious condition with leg fractures and other injuries," Kanimbla Commander George McGuire told Australian Associated Press.

McGuire told the AAP that the helicopter was ferrying an emergency medical team to a remote village as part of relief efforts when it crashed.

McGuire said the transport ship was headed toward the crash site on the southern tip of Nias, which was struck by a deadly earthquake on Monday.

The crew on the Kanimbla cried and bowed their heads in shock in the ship's mess room when McGuire broke the news, AAP reported.