Around 250 people were missing after a boat carrying Rohingya refugees and Bangladeshi nationals capsized in the Andaman Sea, the United Nations' refugee and migration agencies said in a joint statement on Tuesday.
The UN agencies said the trawler carrying around 250 men, women and children reportedly sank due to heavy winds, rough seas and overcrowding.
It had departed from Teknaf in southern Bangladesh and was bound for Malaysia.
"This tragedy highlights the devastating human cost of protracted displacement and the continued absence of durable solutions for the Rohingya," said the United Nations High Commissioner for Refugees, and the International Organization for Migration.
For years, many of Myanmar's Rohingya Muslim minority have embarked on rickety wooden boats to try to reach neighbouring countries, including Malaysia, Indonesia and Thailand, in a bid to flee persecution in Myanmar or overcrowded refugee camps in Bangladesh.
The agencies called on the international community to step up and sustain funding for lifesaving assistance for Rohingya refugees in Bangladesh as well as support for Bangladeshi host communities.
In 2017, Myanmar's armed forces launched an offensive that forced at least 730,000 Rohingya from their homes and into neighbouring Bangladesh, where they recounted killings, mass rape and arson.
A UN fact-finding mission concluded the 2017 military offensive had included genocidal acts.
Buddhist-majority Myanmar has denied genocide, and says the UN fact-finding mission was not objective or reliable.

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