"The two villages were partially burned down," the minister said in his statement, adding that nine of the attackers were killed and four taken prisoner.

The attacks took place near the border with Sudan where the United Nations refugee agency runs a camp for people displaced by the violence in Darfur.

"The witnesses said it was their Arab neighbours who attacked on horseback"

Relief worker
in Chad
Aid workers said the attacks appeared to repeat the pattern of violence that has swept eastern Chad in recent weeks, in which armed Arabs have turned on non-Arab communities. This mirrors the conflict that has killed tens of thousands in Sudan's Darfur since 2003.
   
"The witnesses said it was their Arab neighbours who attacked on horseback," one relief worker, who asked not to be identified, told Reuters news agency.
   
"The government response was pretty strong and there are a lot of Chadian army troops in the zone," he added.
 
Idriss Deby, the Chadian president, has claimed that neighbouring Sudan is supporting and arming the Janjawid and Chadian forces who are fighting a military campaign to end his 16-year rule. Khartoum has denied the accusation.
   
After inter-communal clashes last month, which killed hundreds, Chad's government declared a state of emergency in the affected areas and the capital N'Djamena.
   
Antonio Guterres, the UN high commissioner for refugees, is due to visit eastern Chad on Friday to see some of the camps along the border which house more than 200,000 Sudanese refugees from Darfur, as well as displaced Chadians.