Myanmar's government began harvesting rice from farmland abandoned by Rohingya in northern Rakhine on Saturday, officials said, a move likely to raise concerns about the prospect of return for more than half a million refugees who have fled communal violence in the area.

The border region has been emptied of most of its Muslim residents since late August, when Myanmar's military launched a crackdown on Rohingya rebels that the UN says likely amounts to ethnic cleansing.

Hundreds of villages have been burned to the ground, with more than 600,000 Rohingya -- a stateless group in mainly Buddhist Myanmar -- fleeing across the border for sanctuary in Bangladesh.

Under intense global pressure, Myanmar has agreed to repatriate "scrutinised" refugees who can prove their residence in Rakhine.

But details of the plan remain thin, seeding concern about who will be allowed back, what they will return to and how they will live in a region where anti-Rohingya hatred remains sky-high. 

On Saturday the government began harvesting 71,000 acres of rice paddy in Maungdaw -- the Rohingya-majority area hardest-hit by the violence -- according to state media and a local official. 

"We started harvesting today in Myo Thu Gyi village tract," Thein Wai, the head of Maungdaw's Agricultural Department, told AFP.

"We are going to harvest some paddy fields of Bengalis who fled to Bangladesh," he said using a pejorative term for the Rohingya commonly used in Myanmar.

"We do not know when those Bengalis who fled to other side will come back. That's why we have to harvest," he said, adding that he did not know what government would do with the paddies in the future. 

Workers were bused in from other parts of the country to assist with the harvest, according to the state-run Global New Light of Myanmar.

- 'Deeply disturbed' -

Myanmar has denied charges of ethnic cleansing and defended its military campaign as a counter offensive targeting Rohingya militants who attacked police posts in late August, killing at least a dozen.

But media, rights groups and the UN have documented consistent accounts from Rohingya refugees of atrocities at the hands of Myanmar security officers, who are accused of killing civilians, raping women and torching homes. 

On Friday UN rights experts said they were "deeply disturbed" after speaking to refugees in Bangladesh. 

The accounts they heard "point to a consistent, methodical pattern of actions resulting in gross human rights violations affecting hundreds of thousands of people," said Marzuki Darusman, who chairs the fact-finding mission.

Myanmar's civilian leader Aung San Suu Kyi -- who has no control over the powerful army -- recently created a committee to oversee resettlement in Rakhine, where tens of thousands of other minority groups were also internally displaced by the violence. 

The construction of homes for minorities such as the Mro has begun, according to state media, while Suu Kyi's government has enticed business tycoons to donate to the rebuilding effort. 

But fear abounds that the rehabilitation will sideline the Rohingya -- a group that has suffered under decades of state-backed discrimination.

Myanmar refuses to recognise the Rohingya as a distinct minority, rendering the 1.1-million strong group stateless. 

The army has spread the view that they are foreign "Bengalis" from Bangladesh, despite many having lived in Myanmar for generations.