Malaysia has detained nearly 270 Rohingya refugees whose boat had drifted offshore for nearly two months because of coronavirus lockdowns.
They fled southern Bangladesh in early April but had been unable to dock.
Dozens of those aboard jumped into the sea and tried to swim to land when their damaged trawler was intercepted by the Malaysian coastguard on Monday.
In recent years, large numbers of Muslim Rohingya have fled Myanmar, where they face persecution.
Many have made their way to neighbouring Bangladesh, setting up camp in Cox's Bazar, which is home to around one million Rohingya.
Some have attempted to make their way to Malaysia, a nearby Muslim country which has come to be seen as a safe haven in the region.
In previous years, smugglers have been able to bring tens of thousands of Rohingya illegally into Malaysia. But Malaysia has now refused to allow refugee boats to land, citing the Covid-19 pendemic as a reason.
Boats turned back
A Malaysian coastguard vessel on Monday spotted a suspected migrant boat off the holiday island of Langkawi and was set to push it out to international waters, the AFP news agency reported.
But as the coastguard approached 53 of the Rohingya on board jumped into the sea.
According to a statement issued by a task force overseeing maritime patrols, another 216 Rohingya were found in the boat, along with the body of a dead woman.
Food and water was provided to the migrants and the boat was taken to Langkawi, where all 269 who had been aboard were detained.
The statement also said investigations had revealed that the boat - reportedly a fishing trawler - was damaged "intentionally", resulting in the "push-back effort being halted".
Human rights activists who had been in intermittent contact with those onboard the boat believe around 500 passengers were onboard when the boat left southern Bangladesh.
Slightly more than half that number have now been detained. The others may have been able to evade the coastguard and reach land earlier.
It's not clear how many boats carrying Rohingya have attempted to make the trip to Malaysia this year, but authorities say they have turned back 22 boats. The vessels are often small and cramped, with hundreds of people unsafely packed in.
One Rohingya Muslim who attempted a similar journey earlier this year told the BBC that the boat she was in lacked basic facilities like water and sanitation. Food and water were also in short supply, she said.
She also said crew members would try to conceal deaths on the boat by running both engines to hide the sound of splashing water when bodies were thrown out.
Earlier this year, at least 28 Rohingya refugees died on a boat crammed with hundreds of people. The boat had been drifting at sea for weeks after failing to reach Malaysia.
The Rohingya, who numbered around one million in Myanmar at the start of 2017, are one of the many ethnic minorities in the country and have faced persecution for generations.
The latest exodus of Rohingya escaping to Bangladesh began on in August 2017 after militants from a Rohingya insurgent group launched deadly attacks in Myanmar on more than 30 police posts.