A Rohingya man is taken onto an ambulance. [Photo/chinadaily.com.cn]

Sick and weak after more than two months at sea, some were getting medical attention. "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.

An estimated 7,000 to 8,000 people are being held in large and small ships in the Malacca Strait and nearby international waters, said Chris Lewa, director of the Arakan Project, which has monitored the movements of Rohingyas for more than a decade. She added that crackdowns on trafficking syndicates in Thailand and Malaysia have prevented brokers from bringing them to shore.