Nearly 600 migrants thought to be Rohingya refugees and Bangladeshis were rescued from at least two wooden boats stranded off the coast of Indonesia's northern Aceh province, authorities said on Sunday.
The overcrowded boats, which were carrying nearly 100 women and dozens of children among the refugees, were towed to shore by fishermen after running out of fuel.
"According to the information we have so far, the people on board are from Myanmar. They are Muslim, from the Rohingya community," said Mohammed Arif Mutaqin, spokesman for the Aceh Search and Rescue Agency.
The International Organization for Migration (IOM) said Bangladeshis were also among the migrants, who authorities believe left Thailand about seven days ago. Some died during the journey.
Of those rescued, around 50 were taken to hospital. "In general, they were suffering from starvation and many were very thin," said North Aceh police chief Achmadi.
Some of the migrants had initially believed they had arrived in Malaysia.
"We are hearing the passengers were left close to shore and were told that this is Malaysia and you got what you paid for. They came onshore and found out it wasn't Malaysia," said Mark Getchell, head of the IOM's mission in Indonesia.
Since 2012, more than 100,000 stateless Rohingya Muslims have fled violence and poverty in Myanmar. Most travel in traffickers' boats to Thailand, where they are held by traffickers in squalid jungle camps before a ransom is paid.
An estimated 25,000 Rohingyas and Bangladeshis boarded people-smugglers' boats in the first three months of this year, twice as many in the same period of 2014, the U.N. refugee agency UNHCR said on Friday.
An agency official estimated that around 300 people had died at sea in the first quarter of this year as a result of starvation, dehydration and abuse by boat crews.