Authorities say around 50 Rohingya Muslims from Burma are feared dead after a boat carrying about 70 asylum-seekers capsized off the country's west coast in the Bay of Bengal early on Sunday.
So far, only about eight survivors have been rescued. Family members spent Monday scouring the coastline off western Burma, looking for more victims. The vessel was headed for Bangladesh when it sank.
Activists say thousands of Rohingya have begun leaving Burma, resuming a dangerous seasonal migration.
The U.N. High Commissioner for Refugees says as many as 1,500 have set sail in the past week.
Violence between Muslims and Buddhists in Rakhine state last year killed more than 200 people and left 140,000 homeless.
The maritime migration of the Rohingya is considered one of the biggest movements of boat people since the end of the Vietnam War in the mid-1970s.