KHARTOUM - At least 133 people have been killed and more than 100 wounded in clashes between two groups belonging to an Arab tribe in Sudan’s West Kordofan state, a tribal leader has said.

The clashes between Awlad Omran and Al-Ziyoud groups of the Arab Mesiria tribe began with a dispute over land, Mukhtar Babo Nimr, the leader of the tribe, told Reuters by phone.

“They used guns and heavy weapons in the fighting in the Kwak area of the state of West Kordofan,” he added. Government officials were not immediately available for comment. West Kordofan is the main oil-producing state in Sudan, and borders the turbulent Darfur region and the new state of South Sudan.

Arab tribes, many of which were armed by the government in Khartoum to help end an insurgency by mainly non-Arab rebels in Darfur, have turned their guns against each other in a surge of conflict over resources.

Meanwhile, gunmen on camels have killed 15 civilians and wounded 10 others in an attack in Sudan’s South Darfur, the region’s government said in a statement.

The attack took place in the Hammadeh area 80 kilometres (50 miles) north of the state capital Nyala, the statement carried by official new agency SUNA said Wednesday. “We have formed a commission of inquiry into the killing of the citizens in the Hammadeh area,” state governor Adam Jar al-Nabi told SUNA.

One of those wounded who talked to SUNA from the hospital in Nyala said the group had been visiting family in Hammadeh and were returning on Tuesday when the attack took place. “Gunmen on camelback attacked us and opened fire on the vehicle, and killed 13 people,” the man named as Abdul Karim said.

Two of the casualties died on Wednesday morning from their wounds, he added. The report did not say how many gunmen had attacked the vehicle and gave no indication of their identity.

The troubled western region of Darfur has been wracked by lawlessness since 2003, when ethnic insurgents rebelled against the mostly Arab government in Khartoum, complaining of their marginalisation.

The conflict has claimed 300,000 lives and displaced two million people, according to the UN, and President Omar al-Bashir and his defence minister are wanted by the International Criminal Court for alleged war crimes in the region.

Rising criminality and disputes between Darfur’s various Arab tribes over resources and water have seen the region sink further into lawlessness in recent years.