New Delhi, July 16 -- BANGKOK - Two boats carrying more than 500 Rohingya refugees left Myanmar's Rakhine State in late June and did not arrive anywhere. As of Thursday, the United Nations feared they had sunk - that more than 500 people were gone.

The boats departed within days of each other from Rakhine State's coastline, carrying passengers trying to reach Malaysia or Thailand through one of the world's most dangerous maritime migration routes. The first vessel, with roughly 250 people aboard, lost contact shortly after setting out. The second, carrying about 280 people, is believed to have gone down off Myanmar's Ayeyarwady coast around July 8 - in the middle of monsoon season, when tropical squalls form without warning and the Bay o...