The mainly-Kurdish Syrian Democratic Forces (SDF) announced the start of a long-awaited siege on ISIS stronghold Raqqa, Syria one week after the US confirmed delivery of arms to it.
SDF, a militia dominated by the Kurdish YPG (People's Protection Units), said on Tuesday that it has begun a battle to capture Raqqa.
"The campaign started yesterday [Monday] to liberate Raqqa city," SDF spokesman Talal Silo told Reuters in a telephone interview.
Later on Tuesday, SDF commander Rojda Felat reported that his troops had entered the eastern part of Raqqa.
"Our forces entered the city of Raqqa from the eastern district of Al-Meshleb," he told AFP.
"The advance came after heavy airstrikes by the US-led coalition."
The city was captured by Islamic State (IS, formerly ISIS/ISIL) in 2014, and has since then served as its de facto capital in Syria.
Last week, the Pentagon announced that it started delivering weapons to the SDF, saying they were necessary to capture Raqqa.
The weapons delivered to the YPG, which the US considers a key fighting force against ISIS, include machine guns and assault rifles, Pentagon spokesperson Major Adrian Rankine-Galloway said.
The move was condemned by Turkey, which considers Kurdish militias in Syria and Iraq to be a threat to its national security.
On Tuesday, Turkish Prime Minister Binali Yildirim reiterated Ankara’s objections to arming the SDF, and warned that Turkey would retaliate to any attack by the US-backed group.
The Raqqa offensive is being supported by US-led coalition airstrikes, Silo told Reuters.
“The coalition has a big role in the success of the operations. In addition to warplanes, there are coalition forces working side by side with the Syrian Democratic Forces,” he said.
Syrian news agency SANA reported that 12 civilians were killed on Monday evening after coalition warplanes hit an area near Raqqa on the bank of the Euphrates River.
The report said the civilians were trying to flee their homes in southern neighborhoods of the city in boats when they were hit.
Raqqa, which lies on the northern bank of the Euphrates, is reportedly surrounded from the west, north, and east by SDF forces.
The group started maneuvers to block the city in November.
The US-led coalition said in a statement on Tuesday that the eventual capture of Raqqa would undermine IS’s standing among jihadists.
“It’s hard to convince new recruits that ISIS is a winning cause when they just lost their twin 'capitals' in both Iraq and Syria,” coalition commander Lt. Gen Steve Townsend said, as cited by the statement.
He noted though that once Islamic State militants are defeated in both Mosul and Raqqa, there will still be “a lot of hard fighting ahead.”
IS Iraqi ‘capital’ Mosul remains under siege from the coalition-supported Iraqi Army and allied militias, with bloody battles waged for IS-controlled parts of the west of the city.
The siege has resulted in hundreds of civilians killed and about 700,000 fleeing, according to UN estimates.