Six Islamist groups in Syria have merged to create an Islamic Front following repeated calls for unity from opposition fighters.
Islamists fighting to topple President Bashar al-Assad have forged Syria's largest rebel alliance, pledging to work towards an Islamic state.
The merger of the six Islamist groups comes after repeated calls for unity from opposition fighters and their foreign backers, following advances by regime forces around Syria's main cities of Damascus and Aleppo.
"The 'Islamic Front' is an independent military and social force that is aimed at bringing down Assad's regime in Syria and at replacing it with a just Islamic state," the alliance said in a statement on Friday.
The announcement came after a rebel spokesman, Abu Firas, declared "the complete merger of the major military factions fighting in Syria".
Speaking to AFP via the Internet from the northern province of Aleppo, Abu Firas said the new front bringing together tens of thousands of rebels would have "one policy and one military command".
Among those in the Islamic Front are Aleppo's biggest fighting force Liwa al-Tawhid, the Salafist Ahrar al-Sham and the Army of Islam, which is concentrated around Damascus.
Firas said "the doors are open to all the military factions, and a committee is working to study the entrance of all groups that also want to join" the front.
News of the merger came as anti-Assad protesters took to the streets for weekly demonstrations, this time under the rallying cry "The blood of the martyr (Saleh) unites us".
Saleh died from his wounds on Monday, after an air strike on a building in Aleppo where he and other faction leaders had been meeting.
On the ground, rebels including jihadists seized the town of Deir Attiya on the Lebanese border, the Syrian Observatory for Human Rights reported.
The majority Christian town in the Qalamoun area north of Damascus is home to 10,000 people and is on the strategic route linking the capital to Homs in central Syria.
More than 120,000 people have died in Syria's brutal war, which erupted after Assad's regime launched a brutal crackdown on pro-democracy protests, sparking a brutal insurgency.