In an audio recording posted on Twitter on Tuesday, Abu Mohamed al-Jolani urged an end to clashes that erupted between militants from the so-called Islamic State of Iraq and the Levant (ISIL) and rival militant groups in Syria.

Al-Nusra is the main branch of al-Qaeda in Syria which was selected over the ISIL by al-Qaeda leader Aymen al-Zawahiri to represent the terrorist group.

Earlier in the day, opposition sources said that 34 militants from the so-called ISIL were killed in clashes with rival militants groups in Jabal Zawiya in the northwestern Syrian Province of Idlib.

All the dead are believed to be non-Syrian militants.

Tuesday's deaths come on the fifth day of infighting that began when militants of the so-called Free Syrian Army (FSA) attacked checkpoints and bases manned by the ISIL.

The clashes have been mostly centered in the provinces of Aleppo and Idlib. However, opposition sources say the fighting has now spread to the east.

A recent British defense study showed that about 100,000 militants, fragmented into 1,000 groups, are fighting in Syria against the government and people.

The extracts of the study by defense consultancy IHS Jane's were published on September 16, 2013.

According to the United Nations, more than 120,000 people have been killed in teh foreign-charged war in Syria.

SHI/SHI