ALEPPO, Syria — In a bid to make progress on the ground in the outskirts of Aleppo city that are controlled by the armed opposition, the Syrian regime has been mobilizing additional troops to the suburbs’ fronts since early April.

The regime launched several ground attacks backed by airstrikes by the regime's air force and Russia on towns and cities controlled by the opposition that are near the fighting lines in the north and west of Aleppo. The shelling caused civilian casualties and injuries, and on April 18, a family of five was killed in the town of Urum al-Kubra, where the civil defense forces worked around the clock to rescue those trapped under the rubble as the shelling destroyed many houses.

The regime’s military escalation comes several months after it gained full control of the city of Aleppo following the opposition's loss of the eastern neighborhoods, which the rebels had seized in mid-2012. The loss came as part of a massive military operation launched on Sept. 22 by the regime on the eastern part of the city, which ended with an agreement between the regime and the opposition under the auspices of Russia and Turkey, stipulating the opposition's evacuation of the eastern part of Aleppo. The regime was in full control of Aleppo on Dec. 22, the day the last group of opposition fighters left the city for the Aleppo and Idlib countrysides.

Ahmed Osama Tenzry, spokesman for the armed opposition’s Huriya Brigades, told Al-Monitor, “The regime is seriously considering imposing its control over the northern and western Aleppo outskirts that pose a threat to its existence in the city. It is therefore primarily seeking to fend off the threat posed by revolutionaries to the city. Through its advance, the regime can deprive the rebels of any chance to attempt to launch an attack and enter the city of Aleppo again.”