The powerful Islamic State group has reportedly withdrawn from several villages dominated by a Sunni tribe in Syria's eastern Deir Ezzor province after clashes with tribal fighters.
Fighters of the self-declared jihadist group were pushed out from Abu Hamam, Kashkiyeh and Ghranij, three villages dominated by the Shaitat tribe in the oil-rich province on Friday, activists said.
Activist Ward al-Furati said clashes were still raging on the edges of Deir Ezzor's towns of al-Bukamal, al-Tayyana and al-Mayadeen.
Fighting between members of the Shaitat tribe and the Islamic State began on Wednesday, with tribal members tweeting about an "uprising" against the armed group, that is seeking to establish an Islamic state straddling Syria and Iraq.
The clashes erupted after the Islamic State detained several members of the tribe.
The Shaitat had earlier promised the Islamic State it would not oppose the group, in exchange for the jihadists not harassing or attacking its members.
On Thursday, Islamic State fighters raided the villages, searching houses and kidnapping or capturing an unknown number of people.
A twitter account for the Islamic State in Deir Ezzor posted a photo showing nine people with their heads down and hands tied behind their backs and claimed they were captives from Shaitat who had committed "treachery".
The Syrian Observatory for Human Rights said at least nine Islamic State fighters had been killed in the clashes, and that the group was rallying forces from across the border in Iraq to send in as reinforcements.
The Islamic State has its roots in al-Qaeda but has split from the group and has seized large swathes of territory in both Syria and Iraq.
It faces opposition from other rebel groups in Syria.