More than 65,000 Rohingya Muslims have fled Myanmar's strife-torn Rakhine state amid new reports of atrocities allegedly committed by Myanmar security forces.

The United Nations' relief agency says 22,000 Rohingya have arrived in Bangladesh camps in the past week alone, the largest number since renewed violence broke out Rakhine in October.

Rohingya women and children wait in a queue to collect water at the Leda camp, an unregistered camp for Rohingya in Teknaf, 296 kilometers south of Dhaka, Bangladesh. Credit:AP

Puttanee Kangkun, a researcher with the human rights group Fortify Rights, says she and her colleagues have documented dozens of atrocities during two weeks interviewing Rohingya families in Bangladesh border camps.

"Many witnessed Burmese (Myanmar) soldiers killing loved ones, including children. Some had their throats cut, while others were burned alive," she said.