Nearly 800 migrants have been brought ashore in Indonesia after being abandoned in the Andaman Sea, but other vessels crammed with migrants were sent back to sea.
The move comes despite a UN call to quickly rescue thousands set adrift in Southeast Asian waters.
Smugglers have abandoned ships full of migrants, many of them hungry and sick, in the Andaman Sea following a Thai crackdown on human trafficking.
Thailand is the first stop on the most common trafficking route used by criminals preying on Rohingya Muslims fleeing persecution in Burma, also known as Myanmar, and Bangladeshis seeking to escape poverty.
"The latest information we have is about 794 people were found in the middle of the sea and brought ashore by fishermen at 5am," a search and rescue official in a town in the Indonesian province of Aceh said.
"They are now in a warehouse by the port as a temporary arrangement," Khairul Nova added.
Nearly 1,400 migrants have landed in Aceh on Indonesia's western tip, and over 1,000 have landed in Malaysia.
Aceh is just across the Malacca Strait from Thailand and Malaysia.
However, migrants on two other boats were turned away.
Indonesia's navy prevented a boat with hundreds of migrants on board from entering its waters, an Indonesian military spokesman said.
A vessel carrying around 400 migrants that the Thai navy towed out to sea was heading towards Indonesia, a Thai government radio station reported.
Malaysia, too, has said it would push boats full of migrants back to sea as Malaysian people did not want to see large numbers arriving in the country.
Inter-governmental agencies called on the region's governments to rescue the migrants first and worry about long-term solutions later.
"The situation is very grave," said Joe Lowry, regional spokesman for the International Organization for Migration in Bangkok.
He said: "They have no food, no water and are drinking their own urine.
"This is a game of maritime ping pong with human life.
"We expect governments in the region to find a solution rapidly ... or we will be finding boatloads of desiccated corpses floating around in the Andaman Sea in coming days."
The United Nations yesterday urged governments to fulfil their obligation to rescue those at sea and "keep their borders and ports open in order to help the vulnerable people who are in need".
Both Malaysia and Thailand have called for the support of international organisations in meeting the cost of dealing with the migrant crisis.
