Chadian authorities have, however, denied any military build-up along its border with Sudan, contradicting a statement made by the North Darfur governor to Al Jazeera.
Speaking to Al Jazeera on Monday, the governor said Chad had amassed government forces, in addition to rebels from the Sudanese National Salvation Front, along the Sudan-Chad border.
Chad shares with Sudan a warrior tradition and a history of violent clan warfare where the bearing of arms is common.
The new measures gave regional governors wide-ranging powers to ensure security, including a ban on unauthorised firearms.
"Those illegally holding weapons of war, whoever they are, must immediately hand them over tocracks the competent authorities. Those refusing will risk exemplary punishment," Pascal Yoadimnadji, the prime minister, said in an address to the nation on Tuesday.
The UN refugee agency UNHCR said the inter-communal clashes, linked to a spillover of violence from neighbouring Sudan's Darfur region, risked spiralling out of control and it appealed for an international protection force to be deployed.
Tribals of non-Arab origin are defending
themselves with machetes and sticks
"UNHCR urges the international community to quickly mobilise a multi-dimensional presence in Chad to help protect hundreds of thousands of Chadian civilians and Sudanese refugees, as well as aid workers trying to help them," it said.
President Idriss Deby's government, already facing an armed insurgency he accuses neighbouring Sudan of backing, says repeated cross-border raids by Sudanese Arab militias known as Janjaweed are turning Chad's Arab and non-Arab communities against each other.
Khartoum denies promoting the violence.
Chad and its southern neighbour Central African Republic, which has also fallen victim to the violence from Darfur, have called for the deployment of international peacekeepers.
Yoadimnadji said: "These inter-communal clashes, whose victims run into the hundreds, exceed all proportions and throw into peril national cohesion ... . Entire towns have been burnt and livestock decimated."
|At least 20 villages south of Goz Beida|
town have been attacked by raiders
The attacks mirror the pattern of violence in neighbouring Darfur in western Sudan where since 2003 Arab militia allied to government troops have targeted non-Arab tribes in their campaign against armed rebels.
"We fear the inter-communal hostilities are spiralling out of control and could threaten the entire southeastern region of Chad," UNHCR said.
It said that since November 4, at least 20 villages south of the eastern town of Goz Beida had been attacked by raiders, who were almost always identified by their victims as Arabs and were often long-standing neighbours.
"They are often well-armed, particularly with Kalashnikovs; on horseback, camelback or in trucks; sometimes in military attire, sometimes in civilian attire," UNHCR said.
Since November 7, some 5,000 newly displaced Chadians had converged on a site for internally displaced people in Habile, 45km southeast of Goz Beida.