ALEPPO, Syria, Aug. 9 (UPI) -- An Islamic State assault on a town in Syria's northern Aleppo province has left nearly 40 rival insurgents dead.
IS fighters suffered 10 killed during the assault on Om Hosh, the Syrian Observatory for Human Rights reported Sunday.
U.S.-led coalition airstrikes are reported to have hit IS positions during the assault, which ended after 37 rival rebels were killed, 20 went missing, and the town fell into IS hands. The militants are reportedly attempting to cut off a road linking the city of Aleppo to its northern countryside, which borders Turkey.
U.S. Central Command reports two airstrikes against IS forces near Aleppo on August 6.
SOHR did not clarify the allegiance of the rival rebels, but U.S.-trained and equipped militants have suffered recent setbacks while operating near Aleppo.
The U.S.-led coalition used airstrikes to defend such a force for the first time last week, running close air support for embattled fighters with the New Syria Force and their allies in the Free Syrian Army. U.S. officials believe their attackers to have been members of the Nusra Front, al-Qaida's affiliate in Syria.
The support came days after Nusra Front militants are reported to have captured several members of a U.S.-trained force known as Division 30, including at least two of its leaders.
Though IS started as an al-Qaida affiliate, it became an adversary of the Nusra Front after IS leader Abu Bakr al Baghdadi declared a caliphate in lands captured by the group in Iraq and Syria last year.
The two groups have, however, been known to team up against moderate rebel groups in Syria, as they did last November in Idlib province.
The seizure of Om Hosh comes after IS forces last week captured the town of al-Qaryatain, in central Syria's Homs province, from forces loyal to Syrian President Bashar al-Assad. The capture of the strategic town allows the militants unfettered access to roadways across central Syria.
IS forces still face a large territorial loss north of their self-declared capital of Raqqa, where Kurdish forces, backed by coalition airstrikes and allied Arab forces, seized a major IS supply point on the Turkish border in June. Possession of towns just 30 miles north of Raqqa, however, has gone back and forth between both sides.