Ten members of civil volunteer group Rela that helps officials round up illegal immigrants were arrested Tuesday for robbing Indonesian migrant workers.

Police said they caught the men robbing the workers' quarters in Ipoh, Perak.

"All of them were in uniform ... Some of them tried to escape but were eventually caught," Ipoh's police chief Jalaludin Ibrahim was quoted as saying by the Bernama news agency.

Jalaludin said the men had instructed the workers to gather outside their quarters, then searched the premises for valuables.

"The same Rela gang had conducted an 'operation' there last Saturday and took away some of the belongings of the workers. This time... their leader quickly called the police," he said.

The Indonesian workers lost some RM2,000 ringgit worth of valuables, including electrical appliances, phones and clothes, in the Saturday robbery, Bernama said.

Police said the Rela volunteers had been remanded for six days for investigations.

Migrant workers and rights groups frequently allege harsh and violent treatment by members of the volunteer corps during their numerous raids at workers' quarters to detain illegal immigrants.

There are some 2.5 million legal and illegal foreign workers in Malaysia, and they account for nearly a quarter of the 10.5-million-strong workforce, official figures show.