A senior Syrian rebel commander died last night of wounds he sustained in a government airstrike in Aleppo.
Abdul Qadir al-Saleh was the leader of Liwa al-Tawhid, one of several rebel battalions stationed in the Aleppo area.
Another Liwa al-Tawhid leader, Youssef al-Abbas was killed in the airstrike, which targeted a meeting of senior brigade commanders.
Sources within the rebel group say up to 50 people have been arrested following the apparently targeted strike, on suspicion of being "government informers".
The air strikes came as pro-regime forces mount a concerted campaign to retake rebel-held parts of the capital Damascus and Syria's second city, Aleppo.
Liwa al-Tawhid last week joined calls by a number of Islamist rebel groups for a united front and an end to infighting which has weakened rebel positions in Aleppo, and has since been leading counter-attacks against regime forces.
Recent footage showcasing the increased proficiency of rebel forces in targeting government aircraft showed how the group has made use of anti-tank weaponry to hit helicopters stationed at government-held bases in the area.