22 people were killed including Nadhir (Chieftain) of Dinka Ngok tribe and UN peacekeepers during clashes which took place at the disputed area of Abyei on Sudan- South Sudan border, announced Sudan's Interior Ministry on Sunday.

"The events witnessed by Abyei area led to the killing of Chieftain of Dinka Ngok tribe Kual Deng Majok and two of his companions besides 17 members of Miseriya tribe and injuring of 12 others in addition to the killing of 2 peacekeepers of the UN Interim Security Force in Abyei (UNISFA)," the ministry said in a statement.

The ministry regretted the incident, urging all parties to exercise self-restraint so that security and peaceful coexistence would prevail and peace between the two parties would be restored as for the historical bonds which link them together.

The ministry further explained that "a delegation of Dinka Ngok, led by deputy chair of the joint committee, accompanied by Emir Kual Deng Majok of Dinka Ngok tribe and guarded by a force from UNISFA led by the mission force commander Maj.Gen. Yohannes ( Ethiopian) visited the northern area of Abyei which is dwelled by the Miseriya tribe without notifying the observers. The delegation visited namely Guli, Tajalli and Difra areas."

A group of young men from Miseriya tribe, ridding on motorcycles, gathered and demanded the delegation, which included Emir Kual Deng Majok, to return cows that were confiscated by Dinka Ngok, the statement said, noting that the debate continued for three hours and ended with exchanging fire which caused the incident to take place.

In the meantime, the ruling National Congress Party (NCP) regretted the events witnessed by Abyei area, expressing hope that the death of Kual Deng Majok, Chieftain of Dinka Ngok in those events would not affect on progress in the implementation of the cooperation agreement signed with South Sudan, according to official SUNA news agency.

"This incident should push us for further efforts to implement the agreements signed between the two countries, and it should not be a gateway for a sedition at this area," the agency quoted Yassir Yousif, NCP information secretary, as saying.

The Sudanese Foreign Ministry, for its part, issued a statement on Sunday condemning the incident.

"This unfortunate incident came at a time when the two countries have reiterated their strong political willingness to enhance the cooperation between them in a manner that achieves the interests of the two brotherly peoples, and after they resolved the outstanding security issues and resumed trade and oil cooperation between them. This unfortunate and isolated incident should not affect on this," the statement said.

The ministry further reiterated that the concerned authorities would carry out an urgent, comprehensive, transparent and fair investigation into the incident so that the persons who prove to be involved would be brought to justice.

Chieftain of Dinka Ngok tribe was killed during clashes between his tribe and Miseriya tribe at the disputed oil-rich area of Abyei on Sudan-South Sudan border where peacekeepers from UNISFA were in his company. Endi