 During the widespread chaos and civil war that followed the revolution and led to the erosion of territorial control under the General National Congress (GNC) (which had succeeded the NTC) and the new GNC (NGNC), local loyalists to the Islamic State of Iraq and the Levant (ISIL), which had previously seized the port city of Derna, launched an attack in March 2015 to capture Sirte, which was then occupied by the Libya Shield Force, an NGNC-linked militia.Sirte fell to the ISIL loyalists in May 2015.Following the formation of a new Tripoli-based government, the Government of National Accord (GNA), an offensive backed by the United Nations was launched in May 2016 by GNA-aligned forces, known as the Bunyan Marsous, to recapture Sirte.