At least 16 air strikes were reported late Saturday and early yesterday morning, triggering successive explosions that shook the city and spread panic among residents, activists said.
The US-led coalition often targets IS-held towns and cities in Syria, but the most recent strikes on Raqqa were unusual in their intensity.
In a statement issued early yesterday, the coalition said it had conducted 16 air strikes throughout Raqqa, destroying vital IS-controlled structures and transit routes in Syria.
“The significant air strikes were executed to deny Daesh [the Arabic acronym for IS] the ability to move military capabilities throughout Syria and into Iraq,” said coalition spokesman Lieutenant Colonel Thomas Gilleran.
He added: “This was one of the largest deliberate engagements we have conducted to date in Syria, and it will have debilitating effects on Daesh’s ability to move” from Raqqa.
Raqqa is the de facto capital of the self-styled caliphate declared a year ago by IS in territories it controls in Iraq and Syria.
An IS-affiliated militant website confirmed the strikes on the centre of the city, saying ten people were killed and dozens wounded. It also published purported photographs of the dead, including two boys.
A Raqqa-based anti-IS activist network reported eight civilians were killed by the coalition air strikes, including a ten-year-old child. The report could not be independently confirmed.
The Raqqa is Being Silently Slaughtered network said at least one air strike targeted a group of IS members in the city centre. Another targeted an IS checkpoint while a third destroyed large parts of an IS-held brick factory in the city.
In the remote north-eastern city of Hassakeh, IS suicide bombers detonated an explosives-laden truck near a main power plant yesterday. Syrian state-run news agency Sana reported casualties and material damage in the power plant on the southern edge of the city. Fighting has raged in Hassakeh since IS attacked several southern neighbourhoods held by government troops earlier this month. The violence has forced tens of thousands of residents to flee. The predominantly Kurdish city was split between government forces and Kurdish fighters, who have been fighting IS separately.
The coalition regularly targets IS, which controls about a third of Iraq and Syria.
In Baghdad, a defence ministry statement said government forces repelled an IS attack on a town and a vital dam in Anbar province after IS fighters launched an offensive on the town of Haditha and the nearby Haditha dam yesterday morning.
At least 20 militants were killed in the failed attack, said the statement, which did not provide any further information.