BEIRUT — A Syrian rebel leader who brought together one of the most effective factions fighting President Bashar Assad in the country's civil war has died of wounds from a Thursday government attack on a meeting of rebel leaders outside Aleppo, his followers said Monday.
His death was seen as a serious blow to the rebels amid a gathering government offensive as diplomats pursue efforts to convene international peace talks.
The leader, Abdul-Qadir Saleh, commanded the Tawhid Brigade and was also known as Hajji Marea. He was taken to Gaziantep over the Turkish border after he was wounded in the attack at the rebel-held infantry school.
Another rebel commander was wounded and a third was killed in the attack, which was described in varying reports as an airstrike or a government raid on the building.
Saleh had been seen as an exemplar of the kind of antigovernment leadership emerging from Syria's civil war and as one of the government's most wanted men. His death provoked outpourings of mourning on his followers' social media sites and on YouTube.
A battalion commander from Tawhid, Hassan Abdulsamie Najjar, said in an interview that Saleh died in Turkey on Thursday after being wounded in the chest, but his death was kept secret until he could be buried late Sunday in his hometown, Marea. Others said the death was concealed to maintain morale.
"I carried his coffin in the funeral," Najjar said.
Saleh, a merchant and former army conscript, had organized many local fighting groups to form the Tawhid Islamic brigades, supported by Qatar. Antigovernment activists said he would be succeeded by Mohammed Hamadeen, 38, a former Syrian Army officer from Aleppo, but that was not confirmed by the Tawhid Brigade.
Tawhid had cooperated with both Free Syrian Army groups and Islamic Al-Nusra Front, but had increasingly clashed with the foreign-led extremist group, the Islamic State in Iraq and Syria. That infighting is part of what has allowed government forces to regain in recent days territory long held by the rebels east of Aleppo.
Rebels, including Saleh in a video made shortly before his death, have said the government is being aided by Iranian fighters and militiamen from the Lebanese Shi'ite organization Hezbollah, an allegation the government denies.
"We will not let Iran and Hezbollah advance except on our dead bodies," Saleh told the antigovernment Orient Television last week.
Syria's nearly three-year conflict began with peaceful protests demanding political rights. After a fierce government crackdown, Assad's opponents took up arms. The conflict has now evolved into a sectarian-tinged civil war and a proxy war between Saudi Arabia and Qatar, which support rebel groups, and Iran, which supports the government.
Rebel groups in Aleppo have declared an emergency and ordered all fighters to join the battle to resist the government offensive, which threatens the rebels' hold on the eastern part of the divided city.
The government has also advanced into several long-held rebel suburbs south of Damascus and opened an offensive in Qalamoun, an area north of Damascus bordering Lebanon.
The battlefield tilt in favor of Assad's forces coincides with efforts to rekindle talks in Geneva toward a political settlement.