Assad troops abandon their last military base in Syria’s Idlib province

In the latest blow to the government of President Bashar Assad, the Syrian army retreated Tuesday from its last major base in northeastern Idlib province, abandoning the Mastoumeh stronghold to an Islamist-led rebel force.

The estimated 400 men withdrew with most of their equipment to nearby Ariha, a town of 70,000.

The convoy of 20 or more trucks and at least seven tanks traveled over farm roads through olive groves starting in the middle of the night Tuesday. It came under rebel fire en route, resulting in the loss of several dozen soldiers and a number of armored vehicles, the pro-rebel Masar Press agency reported.

Not until Tuesday morning did rebels attack the camp itself, capturing three tanks and some large artillery pieces, according to a Syrian reporter at the scene whose name McClatchy is withholding for his safety.

Moderate rebel commanders, who were closely monitoring the situation but did not take part in the offensive, said negotiations had been going on for weeks to ensure a complete withdrawal of the army from what was once a key supply road linking Latakia, the province that is dominated by Assad’s Alawite sect, with Aleppo, once Syria’s commercial center and now contested between various rebel groups and the government.

It’s not clear exactly what deal was struck between the military and the rebel forces, which include Jabhat al Nusra, al Qaida’s affiliate in Syria, another extremist group, Jund al Aqsa, the Islamist group Ahrar al Sham and two others.

Heavy fighting continued Tuesday evening as rebels seized at least one checkpoint just outside Ariha and were fighting for a second.

With the loss of Mastoumeh, the government now controls only the Abu Duher airport in the east of the province and a hospital-turned-base in the town of Jisr al Shugour that has been under rebel siege for the past two weeks.

Moderate commanders said they expect the government’s troops to leave Ariha at their earliest opportunity because they no longer can be supplied by road.

Mastoumeh is the latest in a string of defeats for the Syrian military in the past two months. Islamists led by fighters from Nusra seized Idlib, the provincial capital, on March 28. On April 25, a combined force that included U.S.-backed moderate rebels seized Jisr al Shugour, a strategic town on the main east-west highway. Two days later, a combined rebel force seized the Qarmeed base on the same road. Since then, rebel forces in different configurations have seized outposts and checkpoints every few days.

Although some foreign observers credit rebel gains to increased collaboration between three regional powers supporting the rebels – Turkey, Saudi Arabia and Qatar – moderate commanders said the real explanation was closer to the ground. This is that all groups, with the exception of the extremist Islamic State, decided to put aside their past enmities and to organize coordinated assaults on the regime using a joint operations room.

Once a political indoctrination camp for elementary schoolchildren that the army seized in 2011 in the early days of Syria’s unrest, the Mastoumeh base became a symbol of Assad’s resort to violence in May of that year, when townspeople from Ariha marched on it, chanting, “The people want the government to fall.”

Troops opened fire, killing at least 11 civilians.