ALEPPO, Syria — Since July 2, when Fatah Halab (Conquest of Aleppo), formed by the majority of opposition factions in Aleppo, announced the launch of its operations to take full control over the city, Aleppo’s residents have spent their nights listening to the sounds of cannons and planes.

Aleppo has been divided into two parts since the Free Syrian Army arrived in July 2012. The eastern side is under the opposition’s control, and the western side is under the regime’s control. The eastern side includes the richest neighborhoods in Aleppo and government institutions such as the municipal palace, the University of Aleppo and security services. In addition, this part of the city includes military sectors such as the artillery faculty, the Muhallab and Hanano barracks, the military academy and the artillery battalion in the al-Zahra neighborhood.

Opposition fighters often launch their operations at night in order to limit the regime’s use of the air force in such battles. The fiery artillery shells fly through the sky while the city shakes as a result of the surface-to-surface missiles launched by the regime’s forces, or what locals call “elephant missiles” because of the rumbling noise they make when launched.

On July 3, the opposition took control of the Syrian regime-affiliated Scientific Studies and Research Center in the al-Rashideen neighborhood. Weapons are made and developed in this center, and it is considered an impenetrable barrier and an important position to defend the western parts of Aleppo, which the regime controls.