According to Tasnim dispatches, Syrian forces found the tunnel after wresting control of Al-Khafsah village, located 77 kilometers east of Aleppo in northern Syria.
The long tunnel was like an underground town with all the needed facilities, which the terrorists used to shell the army troops as well as civilians, a military source told Tasnim.
Following the recent developments in Aleppo, some 1250 square kilometers of land was fully cleared of the militants, the report added.
The Syrian security forces had encircled Aleppo in July 2016 after closing off the last terrorist-controlled route into the city.
Over the past almost six years, Syria has been fighting foreign-sponsored militancy. UN Special Envoy for Syria Staffan de Mistura estimated in August that more than 400,000 people had been killed in the Syrian crisis until then. The UN has stopped its official casualty count in Syria, citing its inability to verify the figures it receives from various sources.