Jabhat al-Nusra, a group suspected of having links with al Qaeda, helped rebels take over the site part of the 111th regiment base in the Sheikh Suleiman region of Aleppo province, which is on the country's northern border with Turkey, said the Syrian Observatory for Human Rights.

Some fighters on the rebel and army side were killed, while around 140 soldiers fled to another military site in the area, the Observatory added.