Press TV reports.
The recent infighting took place as al-Nusra Front militants engaged in a fierce battle with members of the terrorist group, the Islamic State of Iraq and the Levant (ISIL), in the city situated 310 kilometers (193 miles) northwest of the capital, Damascus.
Meanwhile, gunmen from the Storm of the North Brigade affiliated to the so-called Free Syrian Army (FSA) have declared war on the ISIL terrorists.
The announcement came after the Islamic State of Iraq and the Levant militants stormed the town of Azaz, located five kilometers from the Syrian-Turkish border, on September 18, and killed at least five FSA members.
Syrian opposition activists say tensions have mounted in recent months between the militant groups fighting against President Bashar al-Assad government.
On September 25, thirteen foreign-backed militant groups in Syria announced they do not recognize the authority of the so-called Syrian National Coalition.
The groups include the so-called Free Syrian Army and al-Qaeda-linked Takfiri groups such as the al-Nusra Front, Liwa al-Tawhid, and Ahrar al-Sham.
Syria has been gripped by deadly turmoil since 2011. Reports indicate that Western powers and their regional allies -- especially Qatar, Saudi Arabia, and Turkey -- are supporting the militants operating inside the country.
According to the United Nations, more than 100,000 people have been killed and millions displaced in the violence.
Foreign-backed militants in Syria have clashed with an al-Qaeda-linked group in the northwestern Syrian city of Aleppo as the infighting grows among the armed groups in the Arab country,