33 militants killed in air strikes over Raqqa

Air strikes by France and other nations on the Islamic State (IS) stronghold of Raqqa in Syria since Sunday have killed at least 33 militants, activists say.

The UK-based Syrian Observatory for Human Rights said most died when checkpoints around the city were hit.

It also reported the families of IS leaders had started leaving Raqqa for another of the jihadist group's strongholds, the Iraqi city of Mosul.

An IS-linked news agency has reported no casualties from the air strikes. The Amaq agency said on Monday and Tuesday that French warplanes had only targeted "empty locations".

The Syrian Observatory, which has a network of informants on the ground, said more than 33 militants were believed to have been killed in the strikes, but their bodies were so severely dismembered that it could not give an exact figure.

The IS installations struck - including ammunition dumps and command centres - had been stripped of personnel apart from guards on the gates, it added.

Some of the air and missile strikes may have been carried out by the Russians as well as the French, who began their bombing campaign on Sunday night, two days after IS claimed responsibility for the killing of 129 people in Paris.

The Syrian Observatory also said that IS members and dozens of the families of senior members had begun leaving Raqqa for Mosul because of security concerns.