Syrian opposition forces advanced on the northern town of Khan al-Assal on Saturday, and appeared close to seizing one of the last towns in western part of Aleppo province still held by President Bashar al-Assad's forces.

The regime army has been attempting a slow build-up of troops around the province in order to retake Aleppo city, once Syria's biggest commercial hub. So far Assad's push has been dogged by opposition forces counter-attacks.

Elsewhere in northern Syria, Assad's forces launched a third day of heavy air strikes on the town of Saraqeb in Idlib province. The Syrian Observatory for Human Rights said that by late afternoon, jets had already flown 12 raids over the town. Initial counts said five had been killed on Saturday, three of them children.

Neighboring Idlib and Aleppo provinces are regions in northern Syria that have become a stronghold for opposition forces fighting to end four decades of brutal rule by the Assad family.

It was unclear why Saraqeb has been so heavily targeted, but some local activists suggested this was retaliation for an opposition capture of a nearby army checkpoint.

Others posited that the regime army was trying to hammer areas near a critical road leading to Aleppo in order to distract the opposition forces and be able to bring in supplies to its forces.

Opposition forces have been blockading regime-held areas in Aleppo city, Syria's largest urban centre. Aleppo has been mired in a bloody stalemate since opposition forces launched an offensive in the province last year.

Assad's forces have been on the offensive since last month when the army, backed by militants from Hezbollah, recaptured a border town near Lebanon straddling supply lines between Damascus and Syria's seacoast.

Hezbollah-backed Syrian forces have been bearing down hard on opposition pockets around Damascus and other parts of the central province of Homs, part of a strategy to cement control of a belt of territory between the capital and his stronghold on the Mediterranean coast.

In recent weeks the opposition forces have been making slow but persistent progress in Deraa province in the south.
In Aleppo, near the Turkish border, some opposition forces groups appear to be leading the fight to seize Khan al-Assal, according to activists in the area who asked not to be named.

Assad's forces have responded to the opposition forces advance on Khan al-Assal with a string of air raids in the area that set alight swathes of nearby farmland, according to the Observatory.

It counted at least 12 soldiers and four opposition forces were killed in the latest fighting.

PHOTO CAPTION

A general view shows damaged buildings in Aleppo's Karm al-Jabal district July 18, 2013.

Agencies