As many as 100 people may have lost their lives in a second sinking that follows the loss of more than 100 when a boat carrying 135 sank less than a fortnight ago.
The sinking has yet to be confirmed by independent sources. Some reports say the boat was much smaller and not capable of holding 100 people.
However, news agencies and the BBC are quoting Bangladesh Border Guard commander Lieutenant Colonel Zahid Hasan as saying the vessel was carrying around 110 passengers when it went down around 15 kilometres off Cox's Bazaar.
The port is a popular departure point for Rohingya men and boys sailing south past the Andaman coast of Thailand and Phuket to seek a new life in Malaysia.
Two waves of community violence since June involving close to 200 deaths and the burning of thousands of homes in Burma's Rakhine district have left more Rohingya desperate to flee the repressive Burmese state.
The annual ''sailing season'' between October and April usually puts scores of vessels on the water. Numbers this sailing season are expected to be the largest yet.
Small worn-out fishing vessels capable of holding 50 or 60 tightly packed passengers have been the usual means of heading south.
But according to reliable sources, the people smugglers who specialise in Rohingya are now ferrying them to meet cargo vessels standing offshore in international waters.
Capable of holding as many as 300 people, the cargo vessels provide a safer, faster journey and usually enable passengers to avoid the Thai Navy along the way.
Thai Navy patrols intercept Rohingya boats in Thai waters and ''help on'' those on board with food, water, medical aid or mechanical help - anything to keep them at sea and away from Thailand.
In past sailing seasons, as many as 5000 men and boys have landed in Thailand, where detention and the return of the boatpeople represents a task Thai authorities do not want.
Last sailing season, some vessels did weave through the Navy patrols to land on Phuket and at other spots along the Thai coast.
Those who landed are not considered to be refugees or always even recorded as Rohingya.
Unlike other illegal immigrants, they are not processed through the courts and Immigration systems in a conventional fashion.
What happened to them remains a mystery.