According to the report released by the Britain-based Syrian Observatory for Human Rights, more than 1700 militants were killed in infightings among the al-Qaeda-affiliated Islamic State of Iraq and the Levant (ISIL) and other militant groups in northern and eastern parts of Syria.
The report also indicates that the identity of more than 600 militants killed has not yet been confirmed.
Hundreds of other militants also have gone missing, the report added.
Some 979 members of the al-Qaeda-linked Islamic Front, the al-Nusra Front, and the so-called Free Syrian Army have been killed in infightings with the ISIL or in blasts. At least 5 senior militants were among the dead.
The ISIL militants also executed some 112 rival militants mostly in the cities of Aleppo, Homs, and Idlib.
531 ISIL militants were also killed in January. 34 of them blew themselves up in suicide attacks targeting rival militants and 56 others were executed by militants from the al- Nusra Front and the Free Syrian Army.
On January 27, the activists said that Haji Bakr, a top militant who was the second in command in the ISIL, had been killed in Syria in clashes with rival militants.
The battles among militants have strengthened the view among their Western backers that they cannot be a genuine alternative for the Syrian government.
RA/NJF