The UN rights and refugee chiefs and other top officials called on Indonesia, Malaysia and Thailand on Tuesday to disembark refugees stranded at sea as outrage mounted over Southeast Asia's migrant crisis.
A statement said the three countries and the 10-nation ASEAN regional bloc should "make saving lives the top priority by .. significantly strengthening search and rescue operations" and "facilitate safe disembarkation."
It said the migrants should be housed in safe areas and in humane conditions, given medical care and then individually screened to determine whether they needed protection as refugees, asylum seekers, stateless people or victims of trafficking.
It was signed by the UN High Commissioner for Refugees, Antonio Guterres, the High Commissioner for Human Rights, Zeid Ra'ad Al Hussein, the head of the International Organization for Migration, William L. Swing, and Peter Sutherland, special representative of the UN Secretary-General for international migration and development.
Indonesia, Malaysia and Thailand have drawn international condemnation for turning away boats carrying desperate Rohingya migrants from Myanmar and Bangladeshis, who are now in limbo at sea with little food and nowhere to go.
The statement said more than 88,000 migrants had taken to the sea since 2014, with 25,000 arriving in the first quarter of this year alone.
"Nearly 1,000 are believed to have perished at sea due to the precarious conditions of the voyage, and an equal number because of mistreatment and privation at the hands of traffickers and abusive smugglers," it said.
In the Bay of Bengal, "migrants and refugees are fed only white rice and are subjected to violence, including sexual violence. Women are raped. Children are separated from their families and abused. Men are beaten and thrown overboard."
The UN officials said the destination countries should halt immigration detention and other punitive measures, and also clamp down on traffickers and fight xenophobia.
The Bangladeshis are believed to be mainly economic migrants.
But the Rohingya, a minority in Myanmar, have been fleeing their homes in western Rakhine state after years of sectarian violence and discrimination at the hands of the Buddhist majority. Most head for Malaysia.
Each spring, boats stream southward out of the Bay of Bengal, trying to beat seasonal monsoon storms. Hundreds die every year, according to the UN refugee agency.