BANGKOK: More than 2000 migrants in six boats have now been rescued off the coasts of Indonesia and Malaysia on Sunday and Monday, including women and children weak from a lack of food and water and needing medical treatment.

More than 1000 of them were dumped by traffickers in shallow waters off the Malaysian resort island of Langkawi.

The migrants are believed to be long-persecuted Rohingya Muslims.

Early Monday a boat with 400 men, women and children was found drifting off the Indonesian province of Aceh, only a day after two boats carrying about 600 people washed ashore in the same province.

All of the boats were overcrowded and some people died while on board, authorities said.

Traffickers told some of the migrants to swim ashore while some boats ran out of fuel and were towed ashore, officials said.

Indonesian officials said some of those rescued told how they were beaten and had hot water poured on them and they just wanted to get out of Myanmar as soon as possible, to anywhere where they could seek refuge.

The boats were carrying people from Myanmar and Bangladesh.

Chris Lewa, director of the Arakan Project, which has monitored the movements of Rohingya for more than a decade, said as many as 8000 Rohingya and Bangladesh asylum seekers could be parked on boats in the Malacca Straits, unable to come ashore in Malaysia and Thailand.

She worried that with limited access to food and clean water their health was steadily deteriorating.

In the past their first stop has been in Thailand where smugglers held them captive in jungle camps in brutal conditions while collecting payments, before allowing them to continue their journey to Malaysia, Indonesia or other destinations.

But the discovery of mass graves and dozens of captive Rohingya in Thailand's south has prompted a crackdown that has seen the arrest of several powerful provincial politicians, local officials, a major tourist business operator and investigations into 50 police officers.

- with agencies