The Rohingyas - a distinct Muslim ethnic group who are effectively stateless - have been fleeing Myanmar for decades. But a combination of factors means many are now stranded in rickety boats off the coasts of Thailand, Malaysia and Indonesia with dwindling supplies of food and water.
Also on the boats are thousands of economic migrants from Bangladesh fleeing grinding poverty at home.
Why are the Rohingyas fleeing Myanmar?
While the Rohingyas say they are descendants of Arab traders who have been in the region for generations, Myanmar's governments say they are not a genuine ethnic group but are actually Bengali migrants. Successive Myanmar governments have been introducing policies to repress the Rohingya since the 1970s, according to Burmese Rohingya Organisation UK (Brouk).