According to the military source that cited Russian drone footage, many of the militants from the Turkey-led Euphrates Shield Operation have left Northern Aleppo after the closure of the base.
The military source added that with the large influx of militants in Western Aleppo and Northern Lattakia lately, it is very likely that these militants came from Northern Aleppo.
"In the coming weeks, the terrorists are expected to launch several attacks across Syria, so this transfer of militants will benefit them greatly in the manpower department," he said.
Media sources reported earlier this month that ISIS members joined the Turkey-backed militants of the Euphrates Shield Operation.
Hawar news website released images of ISIL Emir Mostafa Abi, nom de guerre Abu Ayesheh, along with two of his comrades in Homs province, and reported that he was a member of al-Mo'tasem Bellah group.
According to Hawar news, the other two ISIS militants seen in the image were members of Jeish al-Izzah terrorist group.
Meantime, the news website released an image of militants in ISIS uniforms standing among the Euphrates Shield Operation forces.
Hawar news had reported earlier this month that the Turkish Army troops were forcing Arab citizens in Northern Syria to join the Ankara-backed militants of the Euphrates Shield Operation, killing those who do not obey.
It added that the Turkish army killed four civilians in the villages of Kari Sabi town in Northern Syria after they refused to join the Euphrates Shield Operation forces.
Hawar new went on to say that the Turkish soldiers further left the body of the killed Syrian civilians at the border region between Rojava and Bakour in Syria's Kurdistan.
The news website added that the Turkish army intended to send the four killed civilians via border to Rojava but it faced tough opposition by the civilians.