Fighters of the YPG-led Syrian Democratic Forces (SDF) have discovered tunnels inside a mosque in eastern Raqqa.

The mosque was being used as a base by the ISIS gangs until recently. Sniper and mortar attacks were being carried out against SDF forces from the mosque.

The mosque was liberated by the YPG-led SDF with coalition support, but suffered damage.

Footage by YPG Press Office shows that a tunnel, that ISIS had been using to transfer its terrorists and carry out surprise attacks, was discovered 5m underground, inside the mosque.