"The attackers targeted Ahrar al-Sham commander on the road connecting A'zaz and Bab al-Salama border crossing," the sources said.
"The militant commander was killed on the spot," they added.
"There has not been yet any reliable report on the identity of the attackers," the sources said.
Following the victories of the Syrian army and its allies across the country, especially in Aleppo, infighting among the rival militant groups has been in rise in the recent three months.
Reports said earlier today that the Syrian warplanes heavily bombed one of the main supply lines of the ISIL used for transferring weapons, medical equipment and foodstuff to Aleppo from Raqqa.
"The Syrian warplanes tracked and targeted the ISIL procurement route near the villages of al-Jaberiyeh, Afash, and Abu Danneh in the Eastern territories of the province of Aleppo near border with Raqqa," the sources said.
"Meantime, the ISIL strongholds near the villages of Arran, Abu Tatal, al-Madioune and Tal Maksour in al-Bab region , Northeast of Aleppo province were massively targeted in severe sorties of the Syrian fighter jets, which ended in the killing and wounding of many terrorists and destruction of their military vehicles," they added.
S/SH