A Rohingya Muslim sits with her baby in a makeshift tent at the Hakim Para refugee camp in Ukhiya, Bangladesh. Picture: A.M. Ahad/AP

New York - International rights groups on Thursday accused Myanmar's army of widespread rape and other abuses of women and girls in Rakhine state, from where hundreds of thousands of Rohingya Muslims have fled to neighbouring Bangladesh.

Save the Children said interviews with Rohingya refugees in Bangladesh, 60 per cent of who are children, painted "a disturbing picture of the systematic violence, rape and forced evictions" faced by many of them.

"They hit me in the face with a gun, kicked me in my chest and stamped on my arms and legs," it quoted a 16-year-old Rohingya girl as saying in Bangladesh's south-eastern district of Cox's Bazar.

"Then I was raped by three soldiers," the girl said. "They raped me for about two hours and at some stage I fainted."

An estimated 617 000 Rohingya crossed into Bangladesh after the army launched a crackdown on suspected Muslim insurgents blamed for attacks on security posts in Myanmar's restive Rakhine state on August 25.

Save the Children's report, "Horrors I Will Never Forget," includes interviews with other women and children who witnessed atrocities by soldiers against members of the minority group.

It urged Myanmar's government to investigate the abuses ahead of a scheduled meeting of foreign ministers from Asia and Europe in Naypyidaw next week.

The military has staunchly denied that its troops have committed any human rights abuses, including in an investigation report released Monday.

The US-based Human Rights Watch (HRW) also published a report based on interviews with 52 Rohingya women and girls who had fled to Bangladesh, including 29 who reported being raped by soldiers.

Hala Sadak, a 15-year-old refugee, said soldiers stripped her naked and then dragged her from her home to a nearby tree where, she estimates, about 10 men raped her.

All but one of the rapes reported to HRW were gangrapes, and all of the women said the perpetrators were uniformed men working for Myanmar's security forces.

Rights groups have identified specific branches of the military through descriptions of their uniforms, said Richard Weir, HRW's Myanmar researcher, at a press briefing in New York.

The women also described soldiers bashing the heads of their young children against trees, throwing children and elderly parents into burning houses, and shooting their husbands.

HRW's Nisha Varia said women told the group that the perpetrators slapped them, bit their breasts, laughed at them and put guns to their heads during the attacks.

Varia called the military's denial of allegations of mass rape, beatings, extra-judicial killings or destruction of property "outrageous and shameful."

The United Nations has described the actions of Myanmar's military against the Rohingya as "a textbook example of ethnic cleansing."

HRW has called for the UN Security Council to impose a full arms embargo on Myanmar as well as individual sanctions against military leaders responsible for rights violations.

However, US Secretary of State Rex Tillerson advised against sweeping sanctions against Myanmar when he visited the country on Wednesday, and said targeted sanctions on invididuals may be appropriate "if we have credible, reliable information."