The US-backed ‘Syrian Democratic Forces’ (SDF) have are planning a campaign to retake the city of Raqqa, the stronghold of the ISIL militants in Syria.
The coalition of Kurdish and ethnic Arab militias has been gaining ground north of the city.
Raqqa was proclaimed the de-facto capital of the “caliphate” proclaimed by ISIL in 2014.
When will the operation start?
In hours, sources say.
Civilians have been warned to stay away from areas held by ISIL militants.
What support will there be?
The SDF say they will be aided by US-led coalition air strikes.
Turkey, Syria’s closest northern neighbour, is not expected to take part.
Ankara considers the YPG a terrorist organisation and says it will not accept a role for the Kurds in the liberation of Raqqa.
Why are they doing this?
The SDF commanders say the goal of the operation called ‘Angry Euphrates’ is to liberate Raqqa from the militants.
Who is in the SDF alliance?
The US-backed alliance was formed last year to fight ISIL.
The Syrian YPG Kurdish force – one of the most powerful militias in Syria – is regarded as its backbone.
It is dominated by the Kurdish Popular Protection Units (YPG) militia.
It has emerged as a key ally of the US-led coalition in northern Syria over the last two years.