Opposition activists say members of an al-Qaida-breakaway group have withdrawn from parts of the northern province of Aleppo ahead of a possible confrontation with rival factions.

Aleppo-based activists who go by the names of Ibrahim Saeed and Abu Raed say members of the Islamic State of Iraq and the Levant evacuated several towns north of Aleppo, including Azaz near the Turkish border.

The activists and the Britain-based Syrian Observatory for Human Rights say they withdrew Friday.

The pullout came three days after the leader of a powerful al-Qaida-linked group in Syria gave the Islamic State a five-day ultimatum to accept mediation by leading clerics to end infighting or be "expelled" from the region.

Saeed said Islamic State fighters appear to be withdrawing toward their stronghold of Raqqa in northeastern Syria.