Amman: Syria's Al Qaeda-linked Nusra Front has abducted the commander of the Western-backed Jaish Al Tahrir brigade, along with several of his aides and scores of fighters in coordinated raids in northern Syria, Jaish Al Tahrir said on Sunday.
Jaish Al Tahrir was set up in February as part of an effort to forge unity among moderate rebels in the Free Syrian Army (FSA) alliance at a time when a major IS advance threatened their main stronghold near the Turkish border.
The powerful Nusra Front is ideologically opposed to the more moderate FSA rebels and their Western supporters, but occasionally fights alongside them against IS.
Jaish Al Tahrir, which has 4,000 well trained fighters, said their leader Mohammad Al Ghabi and a number of his aides were taken in a house raid in Kfr Nubl in Idlib province Saturday night.
"They were injured and kidnapped and taken to an unknown location," Jaish Al Tahrir said in a statement.
Nusra Front fighters stormed several locations in coordinated raids and set up checkpoints to arrest around 40 fighters, the group said.
The Nusra Front has previously targeted rebel groups supported by the West, leading to the dissolution of the Syria Revolutionaries Front and the Hazzm movement last year.
In March, the Al Qaeda offshoot seized the bases and weapons of the 13th Division rebel group, one of the factions that has received foreign military aid, capturing US-made anti-tank missiles.
Jaish Al Tahrir called on Syria's main rebel groups Al Ahrar Al Sham and others to put pressure on Nusra to release their leader and prevent an escalation in tensions.
They also said they wanted a judicial court that would arbitrate their differences. Nusra Front has accused leaders of Jaish Al Tahrir of participating in a US-led programme to train and equip Syrian insurgents to fight IS. Nusra Front regards the United States as an enemy.
Jaish Al Tahrir called on restraint by its fighters on their main fronts in northern Syria near the Turkish border where they are battling IS militants and fighting the Syrian government army and allied militias in Aleppo countryside and Latakia province.
Meanwhile, Syrian President Bashar Al Assad issued a decree to form a new cabinet on Sunday that kept key ministers in place. The cabinet comes after he appointed on June 22 a new government led by former electricity minister Emad Khamis, a member of Assad's Baath political party since 1977.
The lineup announced on state media keeps the key defence, foreign affairs and interior portfolios unchanged.
Ex-central banker Adeeb Mayaleh, who has played a leading role in defending the local currency after its steep falls against the dollar, was appointed economy minister.
The Syrian conflict has cost the country more than $200 billion in economic losses and damage to infrastructure, driving its GDP down to less than half its 2011 level.
It has also caused the Syrian pound to lose more than 90 per cent of its value despite concerted attempts to support it.
Critics say Syrian governments do not wield much political power in a system dominated by the president and the powerful security forces.
The Damascus-based government controls most of the war-torn country's major population centres in the west, with the exceptions of Idlib and the rebel-held neighbourhoods of Aleppo, once Syria's biggest city.
Kurdish forces control vast areas along the Turkish border, and IS holds Raqqa and Deir Al Zor provinces in the east.