Activists claimed on Saturday that the Syrian air forces carried out a strike in the northern province of Aleppo and killed 15 people.

The Britain-based Syrian Observatory for Human Rights said the incident took place in the rebel-held Sheikh Maksoud district and that among the killed were nine children.

Syria's state-media did not report anything about the incident, but have said some rebels overran Sheikh Maksoud last week after forcing people to flee their houses.

Reports also said upon storming the area, the rebels beheaded a pro-government Muslim imam and hanged his head atop a mosque minaret.

Reports said that the rebels leading the attack were members of al-Nusra Front, an offshoot of al-Qaida in Iraq.

Since last week, clashes have been going on between the Nusra fighters and the Syrian troops, who are trying to wrest back control of the area.