JAKARTA, Indonesia -- Boats carrying nearly 600 Bangladeshis and long-persecuted Rohingya Muslims from Myanmar landed in western Indonesia on Sunday, with some migrants needing medical care, officials and a not-for-profit organization said. Thousands more are believed to be stranded at sea.

Steve Hamilton of the International Organization for Migration in Jakarta, Indonesia's capital, said his teams were racing to the Aceh province sub-district of Seunuddon, where the boats offloaded.

Of the four vessels that arrived, three apparently had been abandoned by the smugglers, and the other ran out of fuel, he said.

Most of the migrants were men, but there also were 98 women and 51 children, officials said, adding many were sick and weak.

"We had nothing to eat," said Rashid Ahmed, a 43-year-old Rohingya man who was on one of the boats. He said he left Myanmar's troubled state of Rakhine with his eldest son three months ago.

"All we could do was pray," he said, crying.

The Rohingya have for decades suffered from state-sanctioned discrimination in Myanmar and are denied citizenship.

Attacks on the religious minority by Buddhist mobs in the last three years have sparked one of the biggest exoduses of boat people since the Vietnam War, sending 100,000 people fleeing, according to Chris Lewa, director of the Arakan Project, which has monitored the movements of Rohingya for more than a decade.

An estimated 7,000 to 8,000 people are being held in large and small ships in the Malacca Strait and nearby international waters, she said, adding crackdowns on trafficking syndicates in Thailand and Malaysia have prevented brokers from bringing them to shore.

Some are held even after family members pay for them to be released.

"I am very concerned about smugglers abandoning boatloads at sea," Lewa said, noting some people have been stranded for more than two months.