KOTA KINABALU (THE STAR/ASIA NEWS NETWORK, REUTERS ) - A search and rescue operation is underway for seven Indonesians who are feared to have drowned after their boat travelling from Malaysia to Indonesia capsized off the port of Tawau in Malaysia's Sabah island.

The seven-metre long boat with 15 people capsized after it was hit by strong waves about 10 minutes after it left Tinagat in Tawau heading towards Sungai Nyamuk in Indonesia at about 6.30pm on Tuesday (Feb 7).

Two survivors, an Indonesian couple, have been rescued so far. The couple, who survived a 24-hour ordeal at sea, said the incident occurred on Tuesday night, but locals only reported it to the Malaysian maritime agency a day later.

Budiman Muslimin, 26, and his wife Hasmida Masaniaga, 24, were found clinging on to a single life jacket by a villager off the coast of Pantai Batu Payung at about 6.30pm on Wednesday.

They are now in stable condition at Tawau Hospital.

On Thursday morning, six bodies - a man, two women and three children - all believed to be passengers on the boat, were recovered by personnel from the Indonesian National Search and Rescue agency.

The bodies have been taken to Nunukan in Indonesia for verification.

As the boat had departed illegally, authorities only became aware of the incident after the couple were rescued.

A search for the remaining seven Indonesians, including several children, is underway in an area seven nautical miles south of Tinagat in Tawau waters.

Searchers are also combing for survivors along the coastal areas.

Tawau police chief Asst Comm Fadil Marsus said the search involved personnel and boats from the Malaysian Maritime Enforcement Agency, marine police and firemen.

Meanwhile, police on Thursday said they have identified several individuals suspected of illegally ferrying the passengers.

Tawau police chief Asst Comm Marsus Fadil said police have set up a special task force to investigate the incident. He said stern action would be taken against the operators or companies involved in ferrying immigrants illegally in and out of Sabah waters.

The incident was the second boat sinking incident in two weeks in Sabah.

On Jan 28, a boat with 31 people, including 28 Chinese tourists, capsized on its way to Pulau Mengalum from Kota Kinabalu.

Two crewmen and 20 tourists were rescued while four people died. A search for five of the missing is still ongoing.