According to the so-called Syrian Observatory for Human Rights on Sunday, the deaths include 650 civilians who lost their lives in the fighting between militants from the so-called Islamic State of Iraq and the Levant (ISIL) and the al-Qaeda-affiliated al-Nusra Front in the north of the crisis-hit country.
The Britain-based group further reported that the names of 5,641 militants have been confirmed while the names of another 1,200 dead fighters have not been verified.
It added that 2,196 of the militants killed belonged to the ISIL, 2,764 belonged to the al-Qaeda-affiliated al-Nusra Front and groups fighting alongside it against the Syrian government and the remainder of the militants were members of other groups.
Clashes between the rival militant groups still continue despite an order by senior al-Qaeda leaders to stop the infighting.
Infighting has plagued militant groups fighting the Syrian government as the army continues to gain more ground.
The army has captured most of the militant-held towns along the mountainous border with Lebanon since its November offensive began.
Syria has been gripped by deadly violence since March 2011. Over 160,000 people have reportedly been killed and millions displaced due to the violence fueled by the Western-backed militants.
The West and its regional allies including Qatar, Saudi Arabia, and Turkey are giving financial and military support to the militants.
Syrian President Bashar al-Assad has recently said the Takfiri war in his country has strongly shifted in favor of government forces as they have made continuous gains in their fight against the terrorists.