KUALA LUMPUR - MALAYSIAN police have detained 13 people, including a Singaporean woman, on suspicion of working for an international syndicate that allegedly smuggled heroin from Pakistan, an official said on Wednesday.

The Singaporean and a Philippine woman were arrested at the Low-Cost Carrier Terminal international airport in Kuala Lumpur on Monday, said Othman Harun, deputy director of the Federal Narcotics Department.

Seven Nigerians, three Malaysians and a Pakistani were subsequently held in separate raids in the city later Monday, he said. The 13 suspects are believed to be members of an international syndicate that traffics heroin from Pakistan and distributes it from Malaysia.

'They are all involved in international trafficking,' Mr Othman told The Associated Press. 'A lot of groups have been operating here.'

Mr Othman said the Singaporean woman, who was detained with about 500g of heroin and was headed to China, is in police custody and may be charged with drug trafficking, an offense that carries the death sentence.

The other 12 suspects have not yet been charged with any crime but are being held under a special preventive act that allows for indefinite detention without trial, Mr Othman said. The act is often used to hold suspected drug traffickers.

Police did not seize any other drugs in the raids but confiscated a car, foreign currency and laptops, Mr Othman said. Investigations showed the Philippine woman was on her way to Pakistan to pick up drugs, he said.

Last year, police detained 12 West Africans and more than 40 locals for drug trafficking after 127 Malaysians were arrested abroad for carrying drugs, Mr Othman said. This year, syndicates operating in Kuala Lumpur switched to using nationals from other countries, including Filipinos, Indonesians and Singaporeans, to transport drugs. -- AP