The Syrian Army, the Lebanese militia Hezbollah and the National Defense Forces played key roles in the attack.

From the view of the government, holding access to the road would have forced opposition fighters from their strongholds in Homs by cutting supply routes.

[23] The exact details of which individuals and institutions oversaw the planning of the operation are less than clear, however, the commander of the Quds force Qasem Soleimani has been reported to be the mastermind behind the Al-Qusayr offensive.

[20] On 21 April, Burhaniya and Saqraja were also captured in the government advance and the Army secured the road linking the Lebanese-Syrian border along the Orontes river to the west of al-Qusayr.

At the same time, a new round of rebel rocket strikes hit the Lebanese towns of Hermel and al-Qasr, in retaliation for the Hezbollah participation in the offensive.

Hezbollah forces were advancing from the Bekaa valley toward al-Qusayr, while the Syrian Army was moving south from Homs in a pincer movement.

[40] On 23 April, more rebel rocket strikes hit the Lebanese town of Hermel,[41] as a Syrian military source insisted that the capture of al-Qusayr was "just days away, at most".

[45] On 29 April, six rockets from Syria hit Macharih el-Qaa in the Bekaa valley, in Lebanon, injuring one person.

[46] On 2 May, clash took place in the Jusiya area near the Lebanese border between rebels and the Syrian army, as well as pro-government militiamen, who also include Hezbollah members.

Fighters from Hezbollah's elite forces also participated in the clashes and were able to take control of most of the villages surrounding the city in the previous days.

[48] Iranian Press TV reported that the military had captured the last major rebel stronghold east of the city, Tal Hanash, and thus completing the encirclement of al-Qusayr.

[52] On 8 May, heavy fighting continued in al-Qusayr, with mediation underway between government forces and some local "elements" to make the rebels withdraw from the town although many were still refusing to leave.

[55] On 10 May, according to a military source, the Army dropped leaflets over the city warning citizens to evacuate al-Qusayr ahead of an assault.

[63] On 13 May, government forces captured the towns of Damina al-Gharbiyah, Haidariyeh and Ish al-Warwar, north of al-Qusayr, allowing them to block supplies to the rebels in the city.

[64][65] On 18 May, the rebels ambushed Hezbollah fighters along the banks of the Assi river on the Syrian side of the Lebanese border while they attempted to enter Syria.

[71] Syrian troops entered the center of the city later in the day, seizing the town's main square and its municipality building, a military source said.

[73] By the second day of the battle, state media claimed they had restored "stability" in the town's east, and was still hunting "remnants of terrorists" in some northern and eastern areas.

Thick black smoke could also be seen from the direction of the air base, north of the city, as government troops fought to retake the facility.

[77] Another opposition activist once again reaffirmed that government forces had captured the municipality building and the city center and had pushed out rebel units out of most of al-Qusayr.

[80] On 22 May, George Sabra, president of the SNC, issued a call for reinforcements to be sent to al-Quasyr stating "Everyone who has weapons or ammunition should send them to Qusair and Homs to strengthen its resistance".

Later, Abu Firas of the Tawid brigade claimed that a total of 300 support units arrived in al-Qusayr, adding that they also sent an ambulance, an antiaircraft weapon and ammunition.

Morale among Army personnel was reportedly high as "news broke" about the killing of al-Nusra Front commander Abu Omar.

[86] The opposition activist group SOHR stated that 76 rebels, 31 Hezbollah fighters, 12 government soldiers and militiamen and eight civilians were killed during the first three days of the fighting.

[93] An Army officer stated that the rebels were confined in a triangle linking Arjun, al-Dabaa and the northern part of al-Qusayr.

[94] On 25 May, government and Hezbollah forces had also reportedly breached rebel defence lines at the al-Dabaa air base from the northwest and entered the facility where fighting was ongoing, according to the Army.

[95] SOHR reported that the fighting was taking place around the base, while rebels were still maintaining control of it, though it was being heavily shelled by government forces.

The fighting than shifted to the village of Haret al-Turkumen, which the Army was trying to capture in order to put al-Qusayr under "complete siege.

[108] On 31 May, the Army captured the village of Jawadiyeh outside al-Qusayr, closing all entrances leading to the town and tightening the government's siege.

A source close to the Syrian military said that the Army was carrying out mop-up operations in the northern quarter of al-Qusayr.

One, to establish a corridor from Damascus to the Mediterranean coast, which is the Alawite heartland, and thus laying the groundwork for a possible new state, which would include about a third of Syria.