Jihadists led by the radical Al-Nusra Front seized a strategic army base in the northern Syrian province of Aleppo yesterday after weeks of fierce fighting, a watchdog said.

The violence came after UN-Arab League envoy Lakhdar Brahimi reported that he held “constructive” talks in Geneva at the weekend with senior Russian and US officials, and ahead of a Friends of Syria meeting in Morocco.

The capture of the base at Sheikh Suleiman dealt a blow to President Bashar al-Assad’s regime in the region as it had been the last major military base west of Aleppo city still under army control.

It also undercut the military influence of the mainstream rebel Free Syrian Army, which was not involved in the takeover, said the Syrian Observatory for Human Rights.

The army used warplanes and tanks, meanwhile, to bombard rebel positions in Damascus province, where the regime is desperate to suppress an insurgency that is inching ever closer to the capital, the monitoring group said.

“Al-Nusra Front, alongside several Islamist rebel battalions linked to it, have seized control of the army base headquarters at Sheikh Suleiman,” Observatory director Rami Abdel Rahman said.

Base 111, with its headquarters in the village of Sheikh Suleiman, sprawls over nearly 200 hectares of rocky hills about 25 kilometres from Aleppo, Syria’s second city.

“It is a significant win for the rebels. It proves the army is still suffering major military losses,” said Abdel Rahman, adding that the rebels seized up to 10 military vehicles and at least one tank.

Other rebel groups also claimed to have captured the base, but Abdel Rahman insisted Al-Nusra and its allies were responsible for its fall. An AFP journalist who covered the clashes around Sheikh Suleiman said many of the fighters were from other Arab countries and Central Asia.

Elsewhere, the army carried out air strikes on suburbs of the capital, amid fierce clashes in Damascus province, said the Observatory.