Tahrir al-Sham has been locked in fierce combat with a rival group of hardline foreign fighters in the town of Harem in rural Idlib province, a local activist said.

Fighting between the two sides has killed a number of people, wounded others and driven civilians to flee the area, fearing for their lives if the clashes expand.

The ongoing clashes between Tahrir al-Sham and the small group of foreign extremists has led to high tension in Harem and surrounding areas, Idlib activist Musab Assaf told Diyaruna.

Most of the foreign fighters are French nationals, some of African origin, he said, and are known to be one of the most hardline groups in northern Syria. They subscribe to al-Qaeda’s ideology, and number no more than 60.

They call themselves "the foreigners" and are led by a French extremist of Senegalese descent named Omar Omsen, also known as Omar Diaby, he added.

The faction recently pledged allegiance to Hurras al-Din, but its members move about freely and are independent of other groups affiliated with Hurras al-Din.

Hurras al-Din was established earlier this year by a number of former Tahrir al-Sham ideologues who rejected the alliance's declared split from al-Qaeda, as they sought to maintain their allegiance to al-Qaeda chief Ayman Zawahiri.

Internal splits surface

The 'foreigners' group has refused to obey the orders of Hurras al-Din emirs, however, who have now asked it to co-ordinate militarily with Tahrir al-Sham as part of a new agreement and truce between the two extremist alliances.

Under this agreement, the 'Islamic State of Iraq and Syria' (ISIS) has temporarily joined forces with Hurras al-Din, which is in turn working with Tahrir al-Sham to repel any attack from the Syrian regime.

This is part of a broader plan, in which Tahrir al-Sham seeks to unite all hardline groups in the region under its banner, Assaf said.

The current tensions erupted a few days after a Tahrir al-Sham patrol detained seven members of the foreigners group, prompting their comrades to set up checkpoints in various areas.

Tahrir al-Sham responded by surrounding the group's main headquarters in Harem, where many were killed or wounded in the ensuing clashes, Assaf said.

According to the most recent reports, he said, Tahrir al-Sham lost 13 of its fighters in the clashes, and five members of the foreigners group lost their lives.

Hurras al-Din did not deploy its elements to support the foreigners group while it was under siege, he noted, and limited its intervention to attempts by its emirs to resolve the dispute amicably and stop the ongoing fighting.

Meanwhile, Assaf said, residents of Harem fled for fear that the situation would escalate further, and that fighting would spill into the streets of the town, pointing out that the two sides have been exchanging artillery and rocket fire.