The UN refugee agency on Monday sounded the alarm for about 400 Rohingya believed to be aboard two boats reported to be out of supplies and adrift on the Andaman Sea.

The agency, also called UNHCR, worries that all aboard could die without efforts to rescue them, said Babar Baloch, its Bangkok-based regional spokesperson.

“There are about 400 children, women and men looking death in the eye if there are no moves to save these desperate souls,” he told The Associated Press. He said the boats that apparently embarked from Bangladesh are reported to have been at sea for about two weeks.

The captain of one boat, contacted by the AP on Saturday, said he had 180 to 190 people on board, they were out of food and water and the engine was damaged.

“They are worried they are all going to die,” said the captain, who gave his name as Maan Nokim.

On Sunday, Nokim said the boat was 320km from Thailand’s west coast. A Thai navy spokesperson, contacted on Monday, said he had not received any information about the boats.

The location is about the same distance from Indonesia’s northernmost province of Aceh on the island of Sumatra, where another boat with 139 people landed Saturday, UNHCR’s Baloch said.

He said they included 58 children, 45 women and 36 men, reflecting the typical balance of those making the sea journey.

Hundreds more arrived in Aceh last month.

There is a seasonal exodus of Rohingyas, usually coming from overcrowded refugee camps in Bangladesh.

About 740,000 Rohingya have fled Buddhist-majority Myanmar to the camps in Bangladesh since August 2017 after a brutal counterinsurgency campaign tore through their communities. Myanmar security forces have been accused of mass rapes, killings and the burning of thousands of Rohingya homes.

International courts are considering whether their actions constituted genocide.

Most of the refugees leaving the camps by sea attempt to reach Muslim-dominated Malaysia, where they seek work. Thailand, reached by some boats, turns them away or detains them.

Indonesia, another Muslim-dominated country where many end up, also puts them in detention.

Baloch with UNHCR said if the two adrift boats are not assisted, the world “may witness another tragedy such as in December 2022 when a boat with 180 aboard went missing in one of the darkest such incidents in the region”.