A boat crammed with migrant workers, believed to be Indonesians, has capsized off Malaysia's western coast, leaving at least 14 people dead, a maritime official has said.

Rescuers were searching on Thursday for dozens of people still missing hours after their small wooden vessel, believed to have been carrying 70 passengers, disappeared near the coastal town of Sabak Bernam in central Selangor state. 

"Local fishermen have rescued 15 people and fished out from the sea 14 bodies - 13 women and one man," Mohamad Aliyas Hamdan, the local head of the Malaysian Maritime Enforcement Agency, told the AFP news agency.

"We have deployed 12 ships and a plane along with some 200 officers to carry out the search and rescue operation for the remaining victims," he said.

Without passports

Al Jazeera's Karishma Vyas, reporting from Kuala Lumpur, said that larger ships would continue to look for survivors into the night.

"Those rescued are all believed to be Indonesian but they are not carrying any passports. This is leading officials to believe that the boat was packed with illegal migrant workers who were returning to Indonesia after working in Malaysia," our correspondent said.

Around two million people, mostly from Indonesia, work in Malaysia illegally, regularly crossing the narrow strip of water between the two countries in barely seaworthy vessels.

"I believe the boat sank because of bad weather and it was overcrowded," Hamdan said. 

Such incidents are common in Malaysia, which has up to 2 million Indonesian migrants working illegally in the country.

The Indonesians work without legal permits in plantations and other industries in Malaysia.

Source: Al Jazeera and agencies