Some 30,000 people from Central African Republic (CAR) have sought refuge in neighbouring Cameroon to escape harassment and child abduction, the United Nations says.

Members of the Mbororo ethnic group that straddles the Cameroon-CAR border first began arriving in Cameroon from CAR in April 2005, but the flow has risen in recent months, aid officials said.

"The eastern and northern parts of CAR are infested with former rebels who frequently assault populations," Jacques Franquin, representative for the UN refugee agency (UNHCR) in Cameroon, told IRIN. "The Mbororo, who are pastoralists, are attacked, their cattle taken away and their children are even kidnapped."

Rebel groups across Africa frequently kidnap children to recruit as fighters or to work as servants or sex slaves, human rights groups say. But William Eteki Mbouma, president of the Cameroonian Red Cross Society, says the children from CAR are kidnapped for ransom. The Mbororo are perceived to be wealthy because of their cattle.

The assailants include former rebels who helped bring CAR President Francois Bozize to power in a 2003 coup, as well as defectors from Chad’s military and Nigerian criminals, Mbouma said.

“They are only interested in the wealth of these pastoralists and children represent a way to constrain parents to pay ransoms,” he told IRIN.

Franquin said Cameroon has deployed elite security forces to protect the local population and the Central Africans, as cross-border assaults are common. The Cameroonian Ministry of Territorial Administration and Decentralisation said security forces would escort all UNHCR teams in the field.

Security forces from Cameroon and CAR in 2005 launched a joint operation to flush out the assailants.

Franquin said it first appeared as though the Mbororo people were roaming Cameroon as pastoralists looking for grazing areas, but the number crossing the border in recent months has escalated and people appear to be settling in.

"They negotiate their settlement conditions themselves with local populations and so far things have worked out well without clashes,” he said. "Inter-ethnic solidarity facilitates foreigners' settlement."

Meanwhile, the UN children’s agency (UNICEF) and the Cameroonian government have begun distributing protein biscuits to children suffering from malnutrition. Many children also have skin diseases, Franquin said.

The Central Africans have settled over a 100 sq km area, which has impeded coordination of humanitarian activities and attempts at registering them.

"It is a challenge to localise all the people scattered in the bush with their herds," Franquin said, noting that poor communications infrastructure has complicated aid efforts.

He said that his team has so far registered some 15,000 refugees and they hope to process all of the new arrival by mid-December. UNHCR plans to open an office in the region by January 2007.