Two boats carrying over 300 members of Myanmar's Rohingya community sank near the Thai-Malaysian border in the last two days. Authorities fear hundreds of casualties.
Malaysian authorities said on Monday that so far, search teams have recovered seven bodies and 13 survivors. Thai officials reported earlier the same day that their search had found four dead.
One boat carrying around 70 people sank in waters near the Thailand-Malaysia border on Sunday, while the fate of another vessel with about 230 passengers, which sank on Saturday, remains unclear.
Rescuers are combing an area of 170 square nautical miles near Langkawi island after a boat with 300 people left Myanmar's Rakhine state three days earlier.
Images released by the agency showed one survivor covered with a sheet and another on a stretcher. Myanmar's impoverished Rakhine state has suffered years of conflict, hunger and ethnic violence mostly targeting the Rohingya Muslim minority community.
Driven out of Rakhine state following a brutal 2017 military crackdown, some 1.3 million Rohingya live as refugees in densely-packed camps in neighbouring Bangladesh.
Malaysian state media Bernama cited Kedah Province police chief Adzli Abu Shah as saying that people initially boarded a large vessel from Myanmar but were instructed to transfer onto three smaller boats, each carrying about 100 people, to avoid detection as they neared Malaysian waters.
The status of the other two boats was unknown, and a search-and-rescue operation was ongoing, he said. Facing violence at home in Myanmar and increasingly difficult living conditions in Bangladesh, Rohingya from both countries regularly attempt perilous journeys by sea.
More than 5,100 Rohingya have taken boats to leave Myanmar and Bangladesh between January and early November this year, with nearly 600 people reported dead or missing, according to data from the UN Refugee Agency.
(With agency inputs)