New footage reveals massive underground tunnels wide and tall enough for vehicles to move through with ease, exposing what is believed to be a major Iranian-led weapons smuggling route. 

Local Syrian security forces uncovered a tunnel linking Iraq and Syria near Al-Bukamal, east of Deir ez-Zor, that residents and media described as constructed by Iranian forces/pro-Iranian militias and used for smuggling weapons, heavy ammunition and other goods across the border. 

The tunnel reportedly extends roughly 500 meters into Syrian territory and was guarded by unidentified vehicles.