By Agencies

Army action that forced half a million Rohingya to flee began before August 25 attack on police post, according to UN.

Myanmar security forces have carried out "well organised, coordinated and systematic" attacks aimed at preventing members of the Rohingya ethnic group from returning, the UN Human Rights office said in a report on Wednesday.

The report, based on interviews with Rohingya who arrived in Bangladesh in the past month, said that "clearance operations" started before armed attacks on police posts on August 25 and included killings, torture, and the rape of children.

More than half a million Rohingya Muslims have been driven out of northern Rakhine State, have had their homes torched, and crops and villages destroyed, the UN said.

UN High Commissioner for Human Rights Zeid Ra'ad al-Hussein - who has described the government operations as "a textbook example of ethnic cleansing" - said in a statement that the actions appeared to be "a cynical ploy to forcibly transfer large numbers of people without possibility of return".

"Credible information indicates that the Myanmar security forces purposely destroyed the property of the Rohingyas [and] scorched their dwellings and entire villages in northern Rakhine State, not only to drive the population out in droves but also to prevent the fleeing Rohingya victims from returning to their homes," the report by his office said.

One 12-year old girl quoted in the report said soldiers and Buddhist civilians surrounded her home before opening fire on it. 

"It was a situation of panic, they shot my sister in front of me, she was only seven years old," the girl said, adding: "She cried and told me to run."

"I tried to protect her and care for her, but we had no medical assistance on the hillside and she was bleeding so much that after one day she died. I buried her myself."

Others cited by the UN described how the attackers warned Rohingya locals to leave immediately or face death.

"You do not belong here, go to Bangladesh. If you do not leave, we will torch your houses and kill you," they said, according to the UN.

The mainly Muslim minority, who live primarily in Rakhine State, is not recognised as an ethnic group in Myanmar, despite having lived there for generations. They have been denied citizenship and are stateless.

According to the UN, more than 500,000 Rohingya have fled Myanmar since its military began an operation ostensibly against Rohingya fighters.