Hundreds of civilians have been killed and thousands of others displaced as US-led SDF forces and Daesh battle in Raqqa. Here's what you need to know.
One of Daesh's major strongholds, Raqqa has been a major battleground since late 2015, when the US-backed Syrian Democratic Forces (SDF) began its offensive on the city. Questions over who will conquer it remain unanswered as clashes intensify.
Why is Raqqa so important?
The central Syrian city of Raqqa has been Daesh's self-proclaimed capital since June 2014. For Daesh, it is the only major Syrian city over which they have full control. Raqqa has also served as their operational centre.
But Raqqa is more than a symbolic stronghold. Located on the northeastern bank of the Euphrates River, the city is strategically important. It is close to the country's largest oil fields in Deir az Zor – another urban centre that Daesh controls. In Raqqa, Daesh refines crude oil, a major revenue source for the group.
Who is fighting Daesh in Raqqa?
US-backed Syrian Democratic Forces (SDF): The SDF alliance was formed in October 2015 to fight against the group. It comprises a mixture of Arab, Assyrian Christian and Syrian factions. Dominating the alliance, an estimated 25,000 fighters who hail from the YPG, the PKK's Syrian affiliate, are also currently leading the battle. The PKK is listed as a terrorist organisation by Turkey, the US, and the European Union.
Since its launch, the SDF has led the campaign to retake Raqqa from Daesh. The forces began a final push the take back the city in June 2017.
The United States: The US-led coalition began supporting SDF since its first offensive against Daesh in 2015. However, support for the YPG dates back to October 2014, when the US first began their fight against Daesh in northern Syria.
The coalition carries out air strikes in Raqqa while providing ground troops, equipment and intelligence support to the SDF. Around 500 US personnel are currently deployed in northern Syria. The coalition in Raqqa includes France, United Kingdom and Germany.
The Syrian regime and allies: This group opened a new front in western Raqqa in June. Russia and Iran support regime air strikes in the city. Although fighting Daesh, the group doesn't work in cooperation with the US-led coalition. A US warplane recently shot down a Syrian army jet, with Washington saying that the jet had dropped bombs near US-backed forces.
How are civilians affected by the fight?
An estimated 200,000 civilians in the city of Raqqa are currently trapped in the city. They face being targeted by US-led coalition air strikes or being used by Daesh as human shields. The SDF has called upon civilians to recapture parts of the northern area of the city. But some videos have emerged in recent weeks which show civilians being killed by Daesh after attempting to flee their homes.
The United Nations said it recorded 300 civilian deaths as a result of "intensified" US-led coalition air strikes between March 1 and May 31. Two hundred of those were displaced families.
According to the UN, air strikes on an old school in the village of Mansoura, sheltering displaced families also killed 200 more civilians in March.
Human Rights Watch says "the US has done very little" to compensate those injured by strikes or the families of those injured" and expressed concern about the use of incendiary phosphorous weapons by the US-led coalition within civilian areas.
So far, 160,000 people in Raqqa have fled their homes.
What happens if Raqqa is recaptured?
US sources say that the SDF has given assurances that Syrian Arabs will govern the city when conquered, and that any gains made won't threaten Syria's neighbouring country, Turkey. In Turkey, two hundred and eighty six people, 133 of whom were civilians have died in YPG-allied PKK attacks in the last year alone, according to Turkey's Interior Ministry.
However Turkey is not convinced. It has long called for co-operation with the Syrian opposition fighting faction, the Free Syrian Army (FSA) – rather than the SDF.
Turkey has refused to take part in the offensive as long as the YPG is involved. It is concerned about change in the region's demographics and the YPG taking control over the area.