The siege of Wadi Deif refers to the siege of two Syrian Army bases, Wadi Deif and Hamadiyah (both just outside Maarrat al-Nu'man), by rebel forces, during the 2014 Idlib offensive of the Syrian Civil War. The first siege of these two bases was broken by the Syrian Army on 18 April 2013. During the siege, rebels detonated several 'tunnel bombs' underneath Army positions surrounding the bases, which was similar to the tactics used during the First World War.