Southeast Asian lawmakers yesterday urged Malaysia to halt a crackdown on migrant workers that has seen more than 6,000 foreigners detained and sparked alarm among rights groups.

Relatively developed Malaysia is a magnet for migrant workeis from across Asia in sectors ranging from construction to agriculture, but several million are believed to be undocumented.

Authorities started rounding up illegal workers after an official programme to register undocumented foreigners ended on June 30.

The latest official figures show 6,038 undocumented workers have been arrested in raids. The two largest groups represented were from Indonesia and Bangladesh, with substantial numbers also from Myanmar, the Philippines and Vietnam.

MPs from a group that brings together Southeast Asian lawmakers pushing for better human rights visited Malaysia on a fact-finding mission, and at the end of the trip made a plea for authorities to end the crackdown.

“This inhumane action must be halted," Philippine Congresswoman Emmi De Jesus told reporters in Kuala Lumpur at the end of the visit.

“Many migrants are living in constant fear. Poor treatment by law enforcement, including indefinite detention in abysmal conditions, are urgent concerns."