JUBA, South Sudan (AP) — Thirty-seven people were killed over the weekend in fighting apparently tied to a land feud in the disputed oil-rich region of Abyei, an official said Sunday. The bloodshed came a week after 52 people died in a land dispute in the same region.

Information Minister Bolis Koch in Abyei, which is claimed by South Sudan and Sudan, said the fighting erupted in Rum-Ameer, Alal and Mijak counties with an attack by armed youth from South Sudan's Warrap state who were backed by fighters loyal to spiritual leader Gai Machiek from the country's Unity state.

Koch said the fighting left 19 people dead and 18 injured Saturday and claimed the lives of 18 more people Sunday, including four women and three children. He said 1,000 head of cattle also were stolen.

“The Abyei Special Administrative Area strongly condemns the terrorist attacks, the heinous killings of innocent civilians, the burning of local markets and residential areas,” Koch said in a statement.

Ethnic violence has been common in the region, where Twic Dinka tribal members from Warrap are contesting for land with Ngok Dinka people in Abyei's Aneet area, located at the border.

Although land is seen as the major driver of the conflict, officials allege the armed Twic young people are being incited by Machiek, an ethnic Neur spiritual leader who has been accused of formenting conflict. He also was blamed for the attack a week ago that killed 53 people, including two U.N. peacekeepers.

Machiek has denied any wrongdoing in interviews with local media.

Sudan and South Sudan have disagreed over control of the Abyei region since a 2005 peace deal ended decades of civil war between Sudan’s north and south. Abyei's status was unresolved after South Sudan became independent from Sudan in 2011, though it is under control of South Sudan.

The region’s majority Ngok Dinka people favor South Sudan, while the Misseriya nomads who come to Abyei to find pasture for their cattle favor Sudan. An African Union panel proposed a referendum for Abyei but there was disagreement over who could vote.