BEIRUT— Rebels groups trying to oust Syrian President Bashar al-Assad have begun fighting with each other in towns across northern Syria, highlighting the growing turmoil between factions favored by the West and those allied to al-Qaida and other jihadist groups.
Fighters from the al-Qaida offshoot, the Islamic State of Syria and Sham (ISIS), overran the border town of Azaz near the frontier with Turkey late Wednesday, triggering the closure of a nearby key border crossing by Turkish soldiers.
The clashes in Azaz erupted after the jihadists seized a German doctor working with an international medical charity, claiming he was a spy, say opposition activists. Then rebels belonging to a group known as Northern Storm, part of the Western backed Free Syrian Army (FSA), responded by freeing the physician, prompting wider gun battles in Azaz.
Northern Storm itself is blamed for the kidnapping a year ago of 11 Lebanese Shiite pilgrims.
Up to a dozen FSA fighters were killed in the fighting, according to opposition activists. At least two jihadists were killed, both foreign fighters, one a Libyan, say opposition activists, who declined to be named for safety reasons.
Azaz is a few minutes from the border crossing into Turkey at Bab-al-Salama, a major supply route for the rebels and one used by relief agencies to transport food and other essential aid into northern Syria. It is also one of the main crossings for refugees fleeing northern Syria.
“By taking Azaz, the Islamic State is a step closer to controlling the crossing. Its objective seems to be taking over the whole countryside north of Aleppo,” opposition activist Abu Louay al-Halabi told Reuters.
After the fighting late Wednesday, FSA rebels reinforced the border crossing, hoping to ensure their control of a frontier post that brings in considerable revenue from “taxes” and smuggling.
Battles throughout the region
Azaz wasn’t the only town that witnessed sharp and violent confrontations between various rebel factions. Jihadist and Islamist units clashed sharply in the eastern Syrian towns of Deir al-Zor and Raqaa on Wednesday, rebel sources said.
Sporadic fighting between rebel factions had become common in the towns since July, but the battles that erupted Wednesday were among the fiercest yet, according to local residents contacted over Skype. They said the jihadists drove other rebel units out of central Deir al-Zor, a town where Assad’s forces still hold the airport.
Even as the rebels fought each other, the Syrian Air Force launched strikes on residential areas of the town, according to the British-based monitoring group, the Syrian Observatory for Human Rights.
In northeast Syria, Kurdish separatists drove jihadists from the village of Alok after four days of intense fighting. In recent weeks, clashes have increased between al-Qaida-affiliated jihadist rebels and Syrian Kurds aligned to Kurdish separatists in Turkey.
The jihadists have sought to exert more control over enclaves they control in northern Syria, while Kurdish militants have tried to seize oil fields currently controlled by jihadists.
The Kurdish militants captured the Syrian town Ras al-Ain on the border with Turkey last month, dealing a serious blow to the al-Qaida-affiliated rebels. In mid-2012, pro-Assad forces withdrew from Kurdish-majority areas in the north and since then Kurdish militants have sought to keep non-Kurdish rebels out of their towns.
Rebel infighting in numerous localized conflicts appears to have intensified since President Barack Obama’s acceptance last week of a Russian-brokered proposal to strip President Assad of his chemical weapons. Rebel leaders had based their battlefield tactics on U.S. strikes, developing plans to take advantage by launching offensives on Assad forces and bases hit by the Americans.
Fighting erupts as US and Russia negotiate
With the U.S. holding off on such air strikes, the tempo and severity of rebel internal strife has picked up.
Last week, jihadists launched an operation in the town of al-Bab to the northeast of Aleppo aimed at expelling FSA-aligned rebels. That operation, dubbed “Cleansing Evil” came days after al-Qaida leader Ayman al-Zawahiri told jihadists to shun the FSA, refuse cooperation with its commanders and to avoid alliances with other rebel fighters backed by Gulf Arab states and the West.
In an audio speech released a day after the 12th anniversary of the 9/11 attacks on New York and Washington D.C., Zawahiri said the United States would try to make the rebels align with “secular parties that are allied to the West.” He added: “I warn my brothers and people in the Syria of unity and jihad against coming close to any of these groups.”
The deepening rift between FSA rebels and jihadists has not, however, prevented ad hoc alliances forming elsewhere in Syria, adding to a picture of increasing chaos and confusion among insurgents.
In early summer, FSA rebels admitted that another al-Qaida affiliate, Jabhat al-Nusra, was in the vanguard of an effort to prevent pro-Assad forces -- assisted by the militant Lebanese Shia militia, Hezbollah -- from re-capturing the strategic town of Qusair.
Jihadists rebels also claim to be spearheading an offensive in the province of Hama, where they say they have overrun a government air defense base and ammunition depot.