At least twelve Indonesians drowned early today after a wooden boat carrying dozens of suspected illegal migrants capsized off the coast of Malaysia, maritime officials said.

The boat, believed to be carrying about 150 people, sank shortly after leaving Port Klang on the west coast en route to Indonesia's Sumatra island across the narrow Straits of Malacca.

Police said they believed the Indonesians were trying to head home for the Aidil Fitri holidays, marking the end of the Muslim holy month of Ramadan.

"We suspect the boat was overloaded. It is a wooden boat meant for carrying goods and not for ferrying people. But it is usually used to carry illegals," local marine police chief Marzuki Ismail told AFP .

Weather conditions were good at the time of the incident.

Malaysia has launched a 60-strong search and rescue operation involving teams of divers.

Marzuki said the Indonesians were en route to Tanjung Balai in north Sumatra.

"We are investigating the incident. We have had a few similar incidents in the past, especially during Aidil Fitri, where many head home," he said.

Media reports also said that six crew members have been detained while marine police were patrolling the area to look for other victims.

So far, they have rescued 137 survivors, of whom 43 are women, 89 men and five children. Nineteen survivors have been sent to the Klang Hospital.

-AFP