Aid workers who carried out an emergency mission to the north of strife-torn Central African Republic found villages abandoned and burned, and evidence of widespread rights abuses, the UN refugee agency said Friday.

"The UNHCR team confirmed widespread lawlessness in the region. Local people spoke of physical assaults, extortion, looting, arbitrary arrest and torture by armed men," said Melissa Fleming, spokeswoman for the UN High Commissioner for Refugees.

The team travelled to a region some 500 kilometres (310 miles) north of the capital Bangui last week.

"We are, in general, increasingly worried about the civilians caught in the middle of the fighting and who are at the mercy of anyone with a gun," she said, adding it remained unclear who was fighting.

Local communities said the spike in violence in the north may have been in retaliation for a clash last month with civilian groups who were trying to protect their families and property.

Around the town of Paoua in the region, the aid workers came upon a scene of devastation.

"They found seven villages burned to the ground and deserted -- and an eighth village partially burned -- with villagers hiding in the bush," Fleming said.

Residents of Paoua and people who fled to the town to escape fighting told UN staff that they were spending the night in the bush for safety reasons and only returning during the day, keeping away from roads to avoid detection, while rain was making living conditions even worse.

Widespread unrest has gripped the country since March, when a coalition of rebel groups known as Seleka deposed president Francois Bozize, who had ruled since a 2003 coup.

Fleming said it was difficult to say how many people had been displaced by fresh violence in recent weeks in the northern region, given security problems and restricted access.

Before the Seleka seized power, the north was home to almost 160,000 people, she noted.

As of Wednesday morning, UNHCR staff had registered 3,020 displaced people in the region around Paoua since fresh violence erupted two weeks ago.

And agency spokesman Babar Baloch told AFP thousands more were believed to have fled from other parts of the nation, adding to the estimated total of at least 206,000 displaced people across the country since December.

As many as 62,000 have also spilled across Central African Republic's borders into neighbouring countries.

Almost 44,000 are in the Democratic Republic of Congo, while a recent wave of more than a thousand people brought the number in Chad to at least 13,000. More than 4,000 Central Africans have also fled to Cameroon.