US-backed Syrian Democratic Forces repelled on April 11 an Islamic State counterattack on the recently captured al-Tabqa Airbase, which lies approximately seven miles south of the IS-held town of al-Tabqa.The SDF first captured the strategic military airport in late March; however, a spate of recent IS ambushes coming from southern al-Tabqa have hindered some advances towards the town.That said, the SDF said on April 11 that it had captured several villages east of al-Tabqa, including al-Ayaad, where several IS fighters were said to have been killed after their tunnel leading towards al-Tabqa was discovered by the SDF.