JUBA, Sudan - Armed men burned and looted the flash-point town of Abyei on Monday after days of violence involving northern and southern troops in the disputed region. Southern Sudan's military said it would defend its territory, while an Arab herdsman said his tribe was in Abyei to stay, an indication that Sudan's peace could crumble before the south's July independence.

Violence flared late last week in Abyei, a no-man's land between north and south Sudan. Southern Sudan voted in January to secede, and the region becomes an independent country July 9. But violence in Abyei is overshadowing the march toward independence.

The U.N. mission in Sudan said armed elements were burning and looting in Abyei. It said the northern Sudanese Armed Forces must fulfill their responsibility to intervene to "stop these criminal acts."

In photos provided by the United Nations, the town appeared deserted except for what appeared to be looters. Some huts appeared to be ablaze; smoke billowed from others. Looters were seen roaming the streets, carrying rifles. Some carried suitcases. Others pulled carts carrying mats, pots and pans, sacks of grain, and even bed frames.

Officials in the north indicated that the two sides could be brought back from the brink even as the south said it would respond with force if its territory was breached.

A powerful Sudanese Arab tribal chief, meanwhile, said that his tribesmen had entered the area with other Arab tribes and that "Abyei is a northern town."

Both north and south claim Abyei, a fertile region near several large oil fields, and its disputed status has long been recognized as a potential trigger for violence. The ethnic African tribe of the Ngok Dinka and the Arab tribe of Misseriah both lay claim to it.

Misseriah tribal chief Mukhtar Babu Nimr dismissed the calls and warnings by southerners and the U.N. Security Council, saying that for months the southerners had violated the Abyei protocol and no one complained.

Tanks from northern Sudan rolled into Abyei on Saturday night, scattering southern troops that were there as part of a joint security unit. The U.N. compound was also hit with mortar fire, and U.N. Secretary-General Ban Ki-moon and the Security Council called for an immediate end to military action.