US-backed fighters have seized the last road into Raqqa, and now say they have completely encircled the Islamic State of Iraq and the Levant’s (ISIL) de facto capital in northern Syria.

The Syrian Democratic Forces (SDF) “have completely surrounded and besieged the Islamic militants inside al-Raqqa city from all sides,” the group said in a statement released late on Thursday.

The Kurdish-led SDF had been advancing from the city’s east after they seized a major stronghold in May, and from the west and north.