Six Rohingya refugees have been killed in a riot in a concentration camp in Malaysia.

KUALA LUMPUR: At least six Rohingya refugees were killed in a head-on collision on a highway in Malaysia as scores of people tried to escape from an immigration detention center where riots broke out earlier on Wednesday.

Authorities say 582 Rohingya have escaped from the Sungai Bakap temporary immigration concentration camp in the northern state of Penang.

They broke down the door and barrier grille and fled.

The Immigration Department said in a statement that 362 of them had been re-arrested.

Police said they have not yet been able to find the cause of the riots and an investigation is underway.

The search for the remaining detainees who escaped from the camp continues.

The dead included two men, two women, a boy and a girl.

They were killed when they were hit by vehicles while trying to cross a highway about 8km from the concentration camp.

There were 664 refugees in the camp, including 137 children.