BEIRUT — Fighters of an Al Qaeda affiliate seized a northern border town in Syria from rival rebels, activists reported Tuesday, as new infighting threatened opposition gains.
The Nusra Front captured the town of Haram in northern Idlib province, said Rami Abdurrahman of the Britain-based Syrian Observatory. The town was seized after weeks of skirmishes between the Nusra Front and their onetime allies among the Western-backed rebel groups, who once united over seeking the overthrow of President Bashar Assad.
A spokesman for some Western-backed groups, Hussam al-Marie, confirmed the infighting. Another rebel group, the Hazzm Movement, said earlier this week that they would no longer work with the Nusra Front.
The infighting apparently began after Nusra Front fighters left a front threatened by government forces near the northern city of Aleppo.
It later worsened after rebels accused Nusra fighters of not helping them hold a town on a strategic highway route in central Syria. Later, Nusra fighters clashed with a rebel group near the northern town of Darkoush, Marie said.
If fighting spreads, it may threaten rebel gains in Syria. Rebel forces already are badly weakened by government victories and infighting that began last winter against militants of an extremist group called the ‘‘Islamic State.’’
The Islamic State group dominates the arc of the Euphrates River from near the Turkish border in Syria deep into neighboring Iraq.