Prime Minister Najib Razak said Thursday he had ordered the Malaysian navy and coastguard to conduct search and rescue operations for boats carrying stricken migrants including ethnic Rohingya from Myanmar.

"I have further ordered (the) Royal Malaysian Navy and Malaysian Maritime Enforcement Agency to conduct search and rescue efforts for Rohingya boats. We have to prevent loss of life," Najib said on his Facebook account.

Malaysia and Indonesia said Wednesday they would no longer turn away boatpeople, a breakthrough in the region's migrant crisis that came just hours after hundreds more starving people were rescued at sea.

Earlier, Myanmar, whose policies toward its ethnic Rohingya minority are widely blamed for fueling the human flow, also softened its line by offering to provide humanitarian aid to stricken migrants.

The U.N. rights and refugee chiefs and other top officials Tuesday called on Indonesia, Malaysia and Thailand to disembark refugees stranded at sea as outrage mounted over Southeast Asia's migrant crisis.

A statement said the three countries and the 10-nation ASEAN regional bloc should "make saving lives the top priority by .. significantly strengthening search and rescue operations" and "facilitate safe disembarkation."

The Indonesian navy prevented a suspected migrant boat from entering the country's waters at the weekend after the arrival of hundreds of Rohingya and Bangladeshis and has stepped up patrols in the area, the military said Monday.

Nearly 3,000 migrants have swum to shore or been rescued off Indonesia, Malaysia and Thailand over the past week, around half of whom have arrived in Indonesia's western province of Aceh. 

Malaysia's foreign minister urged Myanmar on Sunday to hold talks on stemming a flood of boat-people to Southeast Asia, warning it may otherwise call for an emergency meeting on the crisis.

"If necessary, we will call for an emergency meeting," Foreign Minister Anifah Aman was quoted as saying by the state-run Bernama news agency. 

Malaysia's prime minister said on Saturday he would seek help from Myanmar to address the unfolding "humanitarian catastrophe" involving a wave of boatpeople flooding to Southeast Asia, thousands of whom are ethnic Rohingya fleeing oppression in the mainly Buddhist country.

Malaysia, Indonesia, and Thailand have come under increasing pressure to rescue a wave of starving and helpless Rohingya and Bangladeshi migrants after triggering outrage by turning them back out to sea with scarce food and nowhere to go.

A boat packed with desperate Rohingya left Thai waters early Friday bound for Indonesia, authorities said, in line with the kingdom's policy of preventing the migrants from settling in Thailand.

Thai officials gave food and water to hundreds of emaciated Rohingya who have been at sea on the overcrowded boat for weeks. In recent days they were abandoned by their traffickers, who also disabled the engine before fleeing.

U.N. Secretary-General Ban Ki-moon on Thursday urged Southeast Asian countries not to turn back migrants and refugees fleeing on boats, telling them that rescue at sea was an international obligation.

Malaysia and Indonesia have vowed to bar ships carrying migrants from Myanmar and Bangladesh, leaving them stranded in the Andaman Sea and Straits of Malacca.

Malaysia turned away two vessels carrying hundreds of migrants while one boat turned up Thursday in Thai waters, as critics accused Southeast Asian governments of playing a game of "human ping pong" with the lives of desperate boatpeople.

Malaysia and Indonesia have vowed to bar ships bearing desperate migrants from Myanmar and Bangladesh who are flooding into Southeast Asia, triggering warnings that the hardline approach could endanger thousands at sea.

A boat crammed with scores of Rohingya migrants, including many young children, was found drifting in Thai waters Thursday, with passengers telling AFP that several fellow boatpeople had died over the past few days.

Dozens of visibly weak-looking people were on the deck of the stricken vessel, which was found adrift several kilometers (miles) off the southern Thai island of Koh Lipe, in the Andaman Sea, according to AFP correspondents at the scene.