Langkawi, Malaysia: Thailand, Malaysia and Indonesia will continue to push boats holding thousands of migrants back to sea, a senior Thai official said on Wednesday, despite a United Nations (UN) appeal for a rapid rescue operation to avoid a humanitarian crisis.

Several thousand migrants, many of them hungry and sick, are adrift in Southeast Asian seas in boats that have been abandoned by smugglers following a Thai government crackdown on human trafficking, the UN has said.

Malaysia joined Indonesia on Wednesday in vowing to turn back such vessels bearing a wave of migrants.

As the UN’s refugee agency accused regional authorities of playing with lives, more grim accounts emerged from among hundreds of migrants who endured weeks of torment at sea before being dumped by human-traffickers.

Mizanur Rahman, a 14-year-old Bangladeshi boy, said he and a friend spent two agonising months crammed aboard a boat with an estimated 600 other people.

They subsisted on a single plate of rice per day, but were given nothing to eat in the final two weeks, Rahman said.

He spoke in the northern Indonesian region of Aceh, where the two friends washed up this week after traffickers told them to “swim to shore if we wanted to stay alive”.

“We wanted to go to Malaysia, dreaming of a better future of our families. After everything that happened to us, I would now prefer to die here rather than go back home,” Rahman said.

Migrant groups are warning that thousands more men, women and children are believed stuck at sea or at risk of abandonment by smugglers since a Thai police crackdown disrupted people-smuggling routes.

Thailand has called for a May 29 regional summit to address what it called an “unprecedented increase” in arrivals of ethnic Rohingya refugees from Myanmar and impoverished Bangladeshi migrants.

But Malaysia — where more than 1,100 migrants came ashore this week — said it would turn away boats entering its waters unless they were about to sink.

“The policy has always been to escort them out of Malaysian waters after giving them the necessary provisions” including fuel, water and food, First Admiral Tan Kok Kwee of the Malaysian Maritime Enforcement Agency said.

The Indonesian navy already has turned away at least one vessel packed with hundreds of abandoned migrants.

Vivian Tan, Bangkok-based spokeswoman for the UN High Commissioner for Refugees (UNHCR), said the policy was “really worrying”.

“We continue to appeal for countries in the region to share responsibility and avert a humanitarian crisis,” she said.

“The first priority should be to save lives and provide humanitarian aid.”

Joe Lowry, spokesman for the International Organisation for Migration (IOM) in Bangkok, said authorities were playing “maritime ping-pong”.

“What we want is for governments to allow people to disembark so they can be treated and policy can be worked out later,” he said.

Otherwise, “people are going to die in the hundreds and thousands on the sea”.

The UNHCR agency says 25,000 people embarked from Bay of Bengal ports in January-March, double last year’s rate.

Thousands of them are feared left in the lurch by the crackdown in Thailand, which began after the discovery of dozens of dead migrants in jungle graves earlier this month.

Bangladeshi authorities said they seized a fishing trawler filled with 116 of its nationals in the Bay of Bengal near Myanmar on Tuesday.

“They have been on the boat from 15 days to three months,” coastguard station commander Dickson Chowdhury said, adding some had not eaten in a week.

Thousands of Rohingya, a Muslim ethnic group denied citizenship by Buddhist-majority Myanmar, flee annually to escape discrimination and sectarian violence that has targeted them in recent years.

Muhammad Shorif, a 16-year-old Rohingya, fled the squalor of a refugee camp back home in hopes of reaching relatively prosperous Malaysia.

He said he spent a month aboard a smuggling ship jammed with hundreds of others who survived on meagre rations and faced beatings from armed smugglers.

“Six people on our boat died due to illness and hunger, and the captain ordered that their bodies be thrown to the sea,” he said, in Aceh.

The IOM has called for search-and-rescue operations to find stricken migrant boats.

The inter-governmental group has also demanded a coordinated and sympathetic response by Europe as the continent grapples with its own migration crisis originating in North Africa.