Children among the dead as 13 Rohingya refugees are rescued but 25 people remain missing.
At least 12 Rohingya Muslims -- including 10 children -- died when their boat capsized as they attempted to flee to Bangladesh from Myanmar, it was reported on Monday.
The vessel sank near Shah Porir Dwip on the Naf River late on Sunday, according to the International Organization for Migration (IOM) in Bangladesh.
Thirteen people were rescued by border guards but an estimated 25 are still missing, it added.
In another tragedy last month, at least 23 Rohingya died when their boat overturned near Inani beach close to Bangladesh's Cox’s Bazar city.
The refugees are fleeing a military operation in Myanmar amid which security forces and Buddhist mobs have killed men, women and children, looted homes and torched Rohingya villages.
Since Aug. 25, when the military launched a crackdown against Rohingya militants, 515,000 Rohingya have crossed from Myanmar's western state of Rakhine into Bangladesh, according to the UN.
According to Bangladeshi Foreign Minister Abul Hasan Mahmood Ali, around 3,000 Rohingya have been killed in the crackdown.
The Rohingya, described by the UN as the world's most persecuted people, have faced heightened fears of attack since dozens were killed in communal violence in 2012.
Last October, following attacks on border posts in Maungdaw district, security forces launched a five-month crackdown in which, according to Rohingya groups, around 400 people were killed.