Fighters from the Islamic State of Iraq and the Levant (Isil) on Wednesday killed at least five members of the Northern Storm Brigade, a rebel group that controls the border.
Clashes broke out when Isil fighters tried to detain a German doctor they accused of taking photographs of their positions for rival rebels, said Rami Abdul-Rahman of the Syrian Observatory for Human Rights. The doctor, a volunteer in the region, escaped, but the two rebel factions started fighting.
The confrontation in Azaz was one of the most serious clashes between the al-Qaeda affiliate, made up largely of foreign fighters, and the more moderate home-grown rebels trying to topple president Bashar al-Assad.
A Turkish official yesterday said that the Oncupinar border gate – about three miles from Azaz and opposite the Syrian Bab al-Salameh gate – had been closed for “security reasons”.
“There is still confusion about what is happening on the Syrian side. All humanitarian assistance that normally goes through the gate has ceased,” said the official.
Crossings such as Azaz have been a lifeline for rebel-held territories in Syria’s north, allowing in humanitarian aid, building materials and food as well as giving refugees a route out of Syria.
The crossing fell into opposition hands last year when rebels launched an offensive to take the northern business hub of Aleppo. One activist from Azaz said fighting flared again in the border area yesterday when Northern Storm members tried to retake a checkpoint from Isil fighters a mile from the frontier.
“There are very heavy clashes happening now,” he said, citing a rebel commander. Isil supporters also reported fighting and activists near the town said they heard heavy machine-gun fire.
Northern Storm fighters have now been joined by fighters from the Tawheed Brigade who came from Aleppo to try to broker a truce. Tawheed has a large presence in Aleppo, Syria’s largest city, about 18 miles south of Azaz.
“Reinforcements were sent to impose a ceasefire on the two sides,” said Abu Obeida, a Tawheed spokesman. “There is still no ceasefire yet … There are negotiations under way.”
The clashes illustrate the relative strength of the al-Qaeda-linked fighters compared with Syria’s larger but less experienced moderate forces. It also highlights the divisions that have plagued the opposition.
Both dilemmas have left western powers hesitant to supply the rebels with the advanced weapons they need to counter Assad’s better-equipped army.
Isil declared an offensive last week against two other rebel factions, accusing them of attacking its forces and suggesting collaboration with the regime.
“What is worrying are the clashes themselves,” a second Turkish official said. “What we want is to see the various groups put their house in order and focus on the struggle with the regime, because that is the real issue – the violence inflicted by the regime on Syria’s people.”
Many activists and Kurdish forces accuse Turkey of allowing radical groups through its territory to launch attacks on its other foe, Kurdish militias, now operating on the frontier in north-east Syria. Turkey denies those charges.
According to Charles Lister, of IHS Jane’s Terrorism and Insurgency Centre, al-Qaeda-linked fighters make up 10,000-12,000 of the rebels’ estimated 100,000-strong force but wield far more influence because of their better discipline and battle experience.
McCain: Putin’s made Russia the tyrants’ friend
Senior US senator John McCain has accused Russian president Vladimir Putin of allying himself with tyrants and ruling through repression, in a scathing retort to a New York Times editorial by Mr Putin earlier this month.
In an editorial published on news website Pravda.ru Mr McCain, criticised Mr Putin’s policies at home and in Syria, where Russia has repeatedly protected president Bashar al-Assad.
“[Putin] is not enhancing Russia’s global reputation. He is destroying it. He has made her a friend to tyrants and an enemy to the oppressed, and untrusted by nations that seek to build a safer, more peaceful world,” he wrote.
Mr Putin warned a US military strike against Mr Assad could escalate the conflict that has already killed more than 100,000 people.
The hawkish Mr McCain warned Mr Putin in 2011 that “the Arab Spring is coming to a neighbourhood near you” when fraud allegations triggered mass street protests after a parliamentary election.
The senator has also been critical of Mr Putin’s domestic policies. “Putin and his associates … don’t respect your dignity or accept your authority over them. They punish dissent and imprison opponents. They rig your elections. They control your media,” he wrote. He also said members of punk band Pussy Riot, two of whom are in jail for a protest against Mr Putin in a Moscow cathedral, had been convicted on political grounds. “They write laws to codify bigotry against people whose sexual orientation they condemn. They throw the members of a punk band in jail for having the audacity to protest Putin’s rule,” he said.