Nearly 600 people believed to be Bangladeshis and Rohingya Muslims from Myanmar have been rescued from boats drifting in Indonesian waters.
At least two overcrowded boats - with many women and children on board - were towed by local fishermen to the shores of Aceh province on Sunday.
Myanmar - also known as Burma - refuses to recognise Rohingya as citizens.
Hundreds of thousands have fled persecution in recent years, often through Thailand but also by sea.
Indonesian authorities and aid agencies believe the rescued group had been at sea for about a week.
They may have been trying to reach Malaysia, said Steve Hamilton of the International Organisation for Migration.
He said on Sunday that four boats in total were thought to have come ashore.
"People thought they were in Malaysia, it [turned out] they were in Indonesia. They were left behind by the smugglers."
Aceh provincial rescue chief Budiawan told AFP news agency on Sunday: "We received a report from fishermen this morning that there were boat people stranded."
"We despatched teams there and evacuated 469 migrants who are Rohingya from Myanmar and Bangladeshis. So far, all of them are safe."
North Aceh police chief Achmadi said at least 50 of the rescued people were taken to hospital.
"In general, they were suffering from starvation and many were very thin."
One migrant, Rashid Ahmed, told the Associated Press he was a Rohingya and had left Myanmar's Rakhine state three months ago with his son.
"We had nothing to eat. All we could do was pray," he said.
Rohingya Muslims have been fleeing sectarian violence in Myanmar for many years.
In December, the UN passed a resolution urging Myanmar to give access to citizenship for the Rohingya, many of whom are classed as stateless.
The organisation estimates some 25,000 Rohingya and Bangladeshis have boarded smugglers' boats between January and March this year, double the amount as over the same period last year.