The British-based Syrian Observatory for Human Rights said has said the Afghans who were killed during the clash were among the Iranian-backed militia fighters.
The monitor said at least six from Lebanon’s Hezbollah Shi’ite movement and 15 Afghan Shi’ite fighters were killed during the clash.
Earlier, Tehran said thirteen Iranian soldiers were killed in a battle with Islamist militants over a village near the Syrian city of Aleppo.
This comes as earlier reports emerged that suggesting Iran has sent thousands of Shia Afghans to Syria to fight for support of the regime of Bashar al-Assad.
According to the estimates, the number of these fighters is between 10,000 to 12,000 who are mainly illegal immigrants.
The reports also added that Iran has promised citizenship to these fighters and improving the living conditions of their families besides each of these fighters are paid from $400 to $600 monthly wages.