In a remarkable development in the battle between Islamic forces and Western-backed Free Syrian Army brigades in Syria, the Islamic State of Iraq and Greater Syria (ISIS) have issued an ultimatum to the Northern Storm brigade to surrender their weapons by Monday.
In a statement, ISIS called on the brigade to "surrender weapons and repent within a deadline that ends today, to show good will".
The response came quickly from the brigade declaring "all-out war" with the jihadists in the city of Azaz and all areas of the countryside of Aleppo.
A statement issued on Sunday from the operations room of Nahrawan battle in Azaz and Aleppo countryside said: "The door of repentance is open to everyone misled by ISIS to return to their senses and separate from this transgressional group."
"We pledge to anyone who does not disown this group immediately after the issuance of this statement and insists on fighting the people of Azaz, that there will be an all-out war in Aleppo and its countryside – especially against those with the thugs of the al-Ansar brigade," the statement continued.
Sporadic clashes between ISIS, the Nusra Front on one side, and the FSA and Kurdish People's Protection Units on the other have escalated recently in several regions of Syria, culminating in a battle in Azaz in Aleppo countryside earlier in September.
According to unofficial data, the estimated number of foreign fighters who have entered Syria to fight with the armed opposition is now approximately 20,000 from over 50 countries.
Most of those are affiliated with ISIS, followed by the Nusra Front. These two factions, according to Syrian opposition activists, are considered the most radical of the armed forces.
Translated and edited by The Syrian Observer