The statements came amid fresh clashes between ISIS and the terrorist group of Northern Storm brigade in Azaz.

Hours before the statement by the six terrorist groups was made public, hundreds of ISIS terrorists were advancing towards the border post with Turkey near Azaz.

The foreign-backed militant groups Ahrar al-Sham, Liwa al-Tawhid and Jaysh al-Islam all signed the statement urging "our brothers in ISIS to withdraw their troops and vehicles to their main headquarters immediately".

The statement also called for "an immediate ceasefire" between ISIS and the militant Northern Storm brigade in Azaz.

It said both ISIS and the Northern Storm had to "resort immediately to the court, which will remain in session in Aleppo for 48 hours", to settle their differences.

The other three signatories to the statement were Suqur al-Sham, the Furqan brigades and Liwa al-Haq.

The signatories, all extremists, have said they do not recognize the main opposition National Coalition or any other group that operates outside the country.

In separate statements on Thursday, the foreign-backed terrorists in Homs in central Syria also called on the Islamic State of Iraq and the Levant (ISIL), which is a terrorist offshoot of al-Qaeda, to leave the province.

Syria has been gripped by deadly unrest since 2011. Reports say, the Western powers and their regional allies -- especially Qatar, Saudi Arabia, and Turkey -- are supporting the militants operating inside Syria.

According to the United Nations, more than 100,000 people have been killed and a total of 7.8 million displaced due to the violence.

NTJ/