BEIRUT (AP) — Clashes have broken out in northwestern Syria between two of the most powerful insurgent groups raising fears of widespread violence in the rebel-held province of Idlib.

The ultraconservative Ahrar al-Sham said in a statement Saturday that the al-Qaida-linked Levant Liberation Committee is sending reinforcements to the town of Saraqeb and the Jabal al-Zawiya region in preparation for an attack.

The Ibaa News Agency of the al-Qaida-linked group accused Ahrar al-Sham of setting up checkpoints and detaining one of its commanders and his bodyguard, adding that the Levant Liberation Committee removed the checkpoints later by force.

The Britain-based Syrian Observatory for Human Rights said the clashes late Friday were concentrated near the village of Tel Touqan.

The two rival groups have clashed earlier this year before a truce was reached.