KUALA LUMPUR: Ten illegal immigrant Indonesians, including two pregnant women, drowned when their boat capsized in rough seas off Malaysia’s southern coast, maritime authorities said Thursday.

The bodies of five men and five women and the rickety wooden boat they were travelling in washed ashore earlier in the week, marine police official Mohammad Muhi told Agence France-Presse.

The group was believed to be illegally journeying back to Indonesia from Malaysia’s southern state of Johor, Mohammad said.

He added that authorities were engaged in an ongoing search and rescue operation as the ill-fated boat could have carried up to 35 people.

“We found 10 bodies—five men and five women. The victims are Indonesian nationals and we believe they were heading to Indonesia’s Batam island,” he said.

There are some two million illegal immigrants living in Malaysia.

Many of the illegals are poorly paid Indonesians who make a perilous journey across the Malacca Strait only to work long hours in menial jobs shunned by locals.

With one of Asia’s largest populations of foreign labourers, Malaysia relies heavily on immigrants, especially from neighbouring Southeast Asian countries, to clean homes, care for children and work in construction, plantations and factories.