Damascus, Aug 24 (IANS): Syrian tribesmen killed 18 Islamic State (IS) fighters in the oil-rich province of Deir al-Zour in eastern Syria Saturday, media reports said.

The Ukaydat tribesmen succeeded in freeing their leader Sheikh Khalil Jadan, who was kidnapped by IS fighters earlier in the day, and killing 18 of his captors, Xinhua reported citing the country's national television.

Earlier Saturday, the state news agency SANA said IS fighters ambushed the Ukaydat leader who was en route from Deir al- Zour to the capital Damascus. It said that Jadan had previously served as a parliamentarian.

Some of the tribes in the Deir al-Zour province have been deadlocked in battles with the IS which now controls large swathes of that oil-rich province. Earlier this month, the IS killed some 700 tribesmen in two weeks.

SANA said IS militants Saturday killed four people from the Ghranij town in the eastern countryside of Deir al-Zour and mutilated their bodies after beheading them at the town's main square.

The Islamic State, previously known as the Islamic State in Iraq and the Levant, has recently proclaimed to establish an " Islamic Caliphate" in parts of Syria and Iraq, threatening the political geography in the region.

The group, led by Abu Bakr al-Baghdadi who is said to be commanding over 70,000 fighters, said their goal is to establish an Islamic state in Iraq and Syria instead of shunning aside expanding more into other Arab countries.