KUALA LUMPUR, Malaysia (AP) — More than 500 Rohingya refugees escaped from detention in Malaysia early Wednesday following a protest but most have been rearrested, immigration officials said.

The Immigration Department said 528 Rohingya fled after breaking a block door and barrier grill at a temporary detention center in northern Penang state. Police and other agencies were deployed and 362 detainees have been rearrested, the department said in a statement.

“The search for the remaining detainees is continuing,” it said, without giving further details on what sparked the breakout.

Penang police chief Mohamad Shuhaily Mohamad Zain told local media that six detainees were killed while trying to cross a highway. He was quoted as saying the victims were two men, two women, a boy and a girl. The reports didn’t specify the cause of their deaths.

Malaysia, which has a dominant Muslim population, is a preferred destination for Muslim Rohingya fleeing from Myanmar or those seeking to escape misery in refugee camps in Bangladesh.

Malaysia doesn’t grant refugee status, but the country houses some 180,000 refugees and asylum seekers accredited with the UNHCR, including more than 100,000 Rohingya and other Myanmar ethnic groups. Thousands more stay undocumented after arriving in the country illegally by sea.