Damascus, Aug 17 (IANS): The Islamic State (IS) militants have executed 700 tribesmen in Syria's Deir al- Zour provine in the last two weeks, a TV report quoted the Syrian Observatory for Human Rights as saying Saturday.

The IS militants have been carrying out a battle against some of the tribesmen of the oil-rich Deir al-Zour province, bordering Iraq, since the beginning of this month, Xinhua reported.

The 700 people were from the al- Shuaitat tribe, the observatory said, adding that they were executed in last two weeks.

The tribes of Deir al-Zour are an influential force and instrumental in regaining control over the oil-rich province that has for long spiralled out of the government control and fallen to the IS.

The tribesmen battles against the IS have been ignited by the crimes the IS had committed against the civilians and tribesmen of Deir al-Zour.

The IS, previously known as the Islamic State in Iraq and the Levant (ISIL), has recently proclaimed the establishment of an " Islamic Caliphate" straddling Syria and Iraq, and changed its name into the "Islamic State."

Syria has been gripped by deadly conflict since March 2011. Over 160,000 people have reportedly been killed and millions displaced due to the violence.