JUBA, Sudan -- More than 80 people were killed when rebels attacked cattle herders in Southern Sudan, officials said, while hundreds marched in the southern capital to protest the unresolved status of a volatile border hotspot.

The governor of Warrap state said Tuesday that rebels loyal to a high-ranking commander who defected from the southern army in March attacked a village of cattle herders in the remote southern state on Sunday.

Warrap state governor Nyandeng Malek said militia forces loyal to rebel leader Peter Gadet raided the village of Apuk with the aim of stealing cattle.

"They didn't manage to take away cattle," she said.

Like many parts of vast, underdeveloped Southern Sudan, Warrap state is populated by well-armed but impoverished cattle herders, who kept their AK-47s from decades of civil war to protect themselves.

The fighting, which continued on Monday, killed more than 80 rebels and villagers, southern army spokesman Col. Philip Aguer told The Associated Press on Tuesday.

Gadet's rebel group, one of at least seven movements who have declared their intent to overthrow the Juba-based southern government, also claimed responsibility for deadly attacks in oil-rich Unity state last month, where rebels burned huts and looted property.

The southern army's attempts to defeat the array of rebel forces operating across the nearly Texas-sized south have not been successful to date. The Sudan People's Liberation Army's counterinsurgency efforts against a rebel commander in Jonglei state in February left hundreds dead, most of them civilians.

This violence has cast a shadow over the optimism that followed the south's January independence vote, when southerners voted overwhelmingly to form their own nation.

Internal divisions within the south caused great bloodshed during Sudan's north-south civil war, which ended in 2005. Khartoum-backed southern militias razed villages in oil-producing areas and killed villagers allied with the southern liberation movement, which became the south's ruling party.

Also on Tuesday, hundreds marched in Juba to protest a decision by the government to remove the contentious border region of Abyei from the south's transitional constitution as Southern Sudan prepares for independence in July.

Some waved banners reading "There is no more compromise. Abyei is for Southern Sudan."

The protesters delivered a petition to the southern parliament, which is currently considering a draft constitution that will be in place until the new nation holds elections.

"We don't need to fight, we don't need war, but we want our right," said Peter Atem, a protester who said he wants Abyei to join the south.

On Tuesday, four U.N. peacekeepers were shot and wounded while on patrol close to Abyei, U.N. spokesman Farhan Haq said.

Haq said the Zambian peacekeepers were evacuated for immediate medical treatment and their condition was not immediately known. He said the identity of the attackers has not been determined.

The patrol was heading from Diffra to Abyei and the attack took place near the town of Gali, Haq said.

The U.N. has some 9,000 troops and 700 international police officers enforcing a 2005 peace deal that ended the civil war between the ethnic African south and Sudan's Arab-dominated government.

The U.N. condemned the attack and Haq said an emergency meeting of military officials from both sides and the U.N. would be held Wednesday.

The north and south are still negotiating the status of Abyei. Diplomats and analysts fear the dispute over the oil-producing region could ignite a new conflict.

On Sunday, leaders from the north and south agreed to withdraw all "unauthorized forces" from Abyei, where attacks in recent months have left more than 100 people dead and several villages destroyed.

Abyei was promised its own self-determination vote in the 2005 north-south peace deal that ended decades of war. That referendum was set to occur at the same time as Southern Sudan's independence vote, but it did not happen due to a dispute between north and south over who should be eligible to vote.

A land of blond grasslands during the dry season and lush green expanses during the rainy season, Abyei is home to Ngok Dinka subsistence farmers who are loyal to the south.

The region is also used by the Misseriya people, Arab cattle-herders who graze seasonally through Abyei, moving south to water their cattle at the River Kiir, which they call the Bahr el-Arab. Even the name of this treasured water source is contested by these two populations who warily coexist on this land.

Several prominent southern government leaders hail from Abyei, and many southerners feel that the territory should belong to the south when it becomes independent on July 9.

Sudanese President Omar al-Bashir threatened last month he would not recognize the new southern nation if it includes Abyei.