DAMASCUS, Aug. 18 (Xinhua) — Airstrikes in Syria have killed 70 rebels over the past 24 hours in a contested region south of the northern province of Aleppo, state news agency SANA reported Thursday.

As many as 74 airstrikes were conducted over the past 24 hours against military bases the rebels have recently captured south of Aleppo, said SANA, adding that several rebel weaponry and vehicles have also been destroyed during the airstrikes.

The escalated air raids come as part of the Syrian military counter offensive against a series of military bases controlled by rebels in the southern rim of Aleppo.

A military source told Xinhua that the army was advancing toward the military colleges area south of Aleppo, in a bid to drive the Jaish al-Fateh, or the Army of Conquest, out of that strategic region.

Earlier this month, Jaish al-Fateh, a coalition of several radical religious rebel groups, unleashed a wide-scale offensive against several adjacent military bases in southern Aleppo, trying to break a government siege on rebel-held areas east of Aleppo.

The group said it had succeeded in capturing the military colleges, break the siege and open a route through the al-Ramouseh area near the military bases. The government said the rebels' attempt failed as the route is exposed to the fire of the Syrian army.

Meanwhile, the United Nations special envoy on Syria, Staffan de Mistura, urged on Thursday for a 48-hour truce in Aleppo to facilitate humanitarian missions into the city, as all humanitarian efforts have failed during August.

The envoy said the 48-hour pause will be the topic of a meeting that will take place late Thursday between countries working to achieve a cessation of hostilities.

Aleppo, Syria's largest province and once a thriving economic metropolis, has witnessed heavy battles lately as both warring parties have stepped up their game in the hope of grabbing more gains in that key province.