Members of Nusra Front gather before moving towards their positions during an offensive to take control of the northwestern city of Ariha from forces loyal to Syria's President Bashar al-Assad, in Idlib province May 28, 2015. (Ammar Abdullah/Reuters)

Al-Qaeda's Syria franchise, the Nusra Front, has reportedly abducted the commander of the Jaish al-Tahrir brigade, a US-coalition backed rebel group, along with several of his aides and scores of fighters in coordinated raids across northern Syria.

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 Kafr Nabl in Idlib province, northwestern Syria, on 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 powerful Islamist Nusra Front is ideologically opposed to the more moderate Free Syrian Army (FSA) rebels and their Western supporters, but occasionally fights alongside them against the Islamic State.

Jaish al-Tahrir was established in February in an effort to forge unity among moderate rebels in the FSA alliance. At that time, a major IS advance was threatening the FSA's main stronghold near the Turkish border.

The Nusra Front has previously targeted rebel groups supported by the US-coalition.

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 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 program 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 Islamic State militants and fighting the Syrian government army and allied Iranian-backed militias in Aleppo countryside and Latakia province.