Syria conflict: Air strikes on IS-held Raqqa 'kill 18 civilians'
Activists say at least 18 civilians have been killed in air strikes in the Syrian city of Raqqa, the headquarters of so-called Islamic State (IS).
Dozens more people were injured in the raids on Tuesday, according to the Syrian Observatory for Human Rights.
It said it was not able to determine who carried out the strikes, though another group blamed Russian warplanes.
There were further air strikes on Raqqa on Wednesday, but this time reportedly by the US-led coalition against IS.
There were no immediate reports of casualties from the raids, one of which hit the city council building.
The Syrian Observatory reported that Tuesday's air strikes on Raqqa targeted several areas of the city, which has been controlled by IS since early 2014.
Six children were among those killed, the UK-based monitoring group said, warning that the death toll was likely to rise because many of the injured were in a critical condition.
The anti-IS activist group, Raqqa is Being Slaughtered Silently (RBSS), listed the names of 18 people, including two children, who it said were killed in three raids by Russian aircraft on Tuesday. Twenty-eight others were wounded, it added.
RBSS said at least one air strike targeted an area popular among foreign fighters - jihadists who have migrated to Syria to fight for IS.
The US-led coalition said it had conducted four air strikes near Raqqa on Tuesday, hitting an IS tactical unit, headquarters and finance centre, and destroying two oil pump jacks.
IS militants in Raqqa province and neighbouring Aleppo are under pressure from two separate offensives by Russian-backed Syrian government forces and an alliance of Kurdish and Arab fighters supported by the US.
On Tuesday, the militants reportedly drove back government forces around the town of Tabqa, 40km (25 miles) west of Raqqa, after two days of fierce clashes that left 40 soldiers and allied militiamen dead.
The IS-linked Amaq news agency posted video purportedly showing militants in control of the Thawra oil field, which the government forces recaptured on Sunday.
Fighters from the Kurdish-dominated Syrian Democratic Forces (SDF) are meanwhile besieging IS-held Manbij, 110km (70 miles) to the north-west.
At least three suicide bombers attacked SDF positions outside the town on Tuesday, according to the Syrian Observatory.
In a separate development on Wednesday, Syrian President Bashar al-Assad asked Electricity Minister Emad Khamis to form a new government.
The official Sana news agency gave no reason for the decision to replace Wael al-Halqi, who has been in post since 2012.
However, the move comes two months after parliamentary elections were held in government-controlled areas, which the opposition denounced as illegitimate.