Raqqa: Syrian Kurdish-led forces launch offensive on IS 'capital'
A US-backed alliance of Kurdish and Arab fighters has launched an offensive to capture the jihadist group Islamic State's Syrian stronghold of Raqqa.
Spokesmen for the Syrian Democratic Forces (SDF) said the assault began on Monday, with forces advancing on several fronts.
A monitoring group reported clashes in the east of Raqqa and at a military base on the northern outskirts.
The US-led coalition was supporting the assault with air strikes, it said.
The SDF, which is says it is not aligned with Syria's President Bashar al-Assad or the rebel forces seeking to overthrow him, has driven IS from about 6,000 sq km (2,300 sq miles) of northern Syria over the past year.
IS seized Raqqa in early 2014, months after it became the first Syrian provincial capital to fall to the rebels in the six-year civil war.
The jihadist group established the city as the de facto capital of its "caliphate" and implemented a strict interpretation of Islamic law there.