The United Nations refugee agency said Friday that more than 70 Rohingya were feared dead or missing at sea after their boat capsized off Indonesia’s coast this week, but an Indonesian rescue official doubted there were any victims.

Indonesia ended its search-and-rescue operation on Thursday after bringing ashore a total of 75 Rohingya over two days after their wooden boat flipped near the coast of Aceh province on Wednesday.

However, the U.N. refugee agency UNHCR and the International Office for Migration (IOM) said in a joint statement that some rescued refugees from the persecuted and stateless Myanmar minority group had told authorities there had been 151 of them on the boat.

“UNHCR and IOM are very concerned about the potential loss of life as rescued refugees said the ship was actually carrying 151 people,” the joint statement said.

UNHCR’s Asia-Pacific spokesman, Babar Baloch, said if the agencies’ fears came true, the scale of the disaster would be “shocking.”

“If confirmed, this would be the biggest maritime tragedy in Asian waters so far this year,” he said on social media platform X.

Ther U.N. refugee agency’s representative to Indonesia, Ann Maymann, thanked the Southeast Asian country for saving lives “and demonstrating statecraft has human values at its core.”

“I plea[d] for the search efforts to continue in the hope of finding survivors and giv[ing] the perished a dignified burial,” she said in a post on X.

UNHCR and IOM also said that Indonesia had “demonstrated a strong humanitarian side,” adding that they had sent their teams to West Aceh regency to assist the local government in providing help to the victims.

This latest incident occurred amid the increasing arrival of Rohingya refugee boats in Indonesia.

“In 2023 alone, more than 2,300 Rohingya refugees arrived [in Indonesia], with a significant increase from November onwards. This number exceeds the number of arrivals in the previous four years as a whole, UNHCR and IOM said.

The Rohingya have been accommodated in locations across Aceh, according to the UNHCR.

In January, the UNHCR reported that 569 Rohingya refugees had died or gone missing at sea in 2023 while attempting to flee from Myanmar or Bangladesh.

The Rohingya have been fleeing violence and oppression in Myanmar for years.

Following a 2017 military offensive in Myanmar’s Rakhine state, about 740,000 Rohingya fled across the border to Bangladesh. Now, close to 1 million Rohingya refugees live in crowded camps in southeastern Bangladesh.

Many desperate Rohingya board human smuggling boats to leave overcrowded refugee camps in Bangladesh, in search of better lives in other countries including Malaysia and Indonesia.

In recent months, some locals in Aceh have pushed back against hosting the refugees, saying there are not enough resources for all of them.

However on Wednesday, when the overturned boat was spotted in West Aceh, the head of the local fishing community issued a written order for Acehnese fishermen to assist the Rohingya.

“For humanitarian reasons, we are obliged to help those who suffer misfortune at sea, whoever they are” Azwir Nazar, secretary general of Panglima Laot, a traditional institution focusing on the welfare of fishermen.

The captain of the search-and-rescue ship, Supriadi, said his team’s mission was humanitarian because the refugees were in an “emergency situation following the boat disaster.”

He took issue with the UNHCR and IOM’s contention that 76 people may have perished or were missing at sea, because the 69 (of 75) refugees rescued Thursday “had clear coordinates provided by fishermen who witnessed the refugees in distress.”

And that, he told BenarNews, begs the question: “If there are still victims, where are they located?”

“Has the information about the 150 people been fully verified for accuracy? If it is indeed true, where are they located, and we are ready to search for them,” Supriadi, who has just one name, said.

For now, though, “The mission [has] concluded with the discovery of 69 individuals from the overturned vessel on Thursday,” he said.

Six Rohingya were rescued Wednesday. The Rohingya rescued on Thursday had been clinging to their wooden boat for nearly a day and were suffering from hunger and dehydration.

A video taken by a local fisherman on Wednesday showed more than 50 of them standing on the overturned hull of the barely visible boat as they frantically waved for help.

The two U.N. agencies, UNHCR and IOM, on Friday again called on countries to advocate for joint efforts to rescue all people in distress at sea across the region.

“UNHCR and IOM are strengthening efforts to provide humanitarian assistance and emergency protection to refugees arriving in Indonesia,” their statement said.

“UNHCR and IOM express their appreciation to the Indonesian authorities and local communities for their efforts to save the lives of refugees from capsized boats in West Aceh.”

Indonesia is not a signatory to the 1951 Refugee Convention, but has a long history of hosting refugees from various conflicts. It allows refugees to stay temporarily, while they wait for a third country to resettle them, a process that can take years.

Shailaja Neelakantan in Washington contributed to this report.