The majority-Shia towns of Nubl and al-Zahraa, with a combined population of 35,000–60,000,[17][18] were placed under siege by the Free Syrian Army (FSA) opposition group, beginning in July 2012.

[23] They also advanced into the eastern outskirts of Nubl, which they targeted with dozens of mortar and hell-cannon shells after capturing buildings that were part of the government's first line of defense.

The attack was repelled by National Defence Forces (NDF) and Hezbollah troops, ultimately resulting in the deaths of 14 rebels and 11 pro-government fighters.

[32] During the fighting in February 2015, 18 members of the Iraqi Shiite militant group Harakat Hezbollah al-Nujaba were reportedly killed while defending Nubl and Al-Zahraa.

[36] At the same time, Hezbollah and pro-government fighters from Nubl and al-Zahraa launched their own assault and reportedly managed to gain some ground on the outskirts of the nearby town of Bayanoun.

[18] The pro-opposition Syrian Observatory for Human Rights (SOHR) reported that the advance, which also cut the last northern rebel supply route from Turkey to Aleppo city, was assisted by "heavy" Russian air strikes.

An opposition politician described the government's encirclement of Aleppo as a "horrible development",[5] while in contrast the mayor of Nubl stated the rebel siege was "cruel and caused much hardship".

[40] In all, more than 500 Russian and Syrian air strikes and barrel bombs bombarded rebel positions during the intensive two-day offensive to break the siege.

[41] The day following the end of the siege Nubl and al-Zahraa, the Syrian government advanced east and captured the town of Mayer[42] as well as reportedly Kafr Naya.