IS claim of attack in Nice 'vague': analysts

The claim by the Islamic State group that it was behind the truck massacre in Nice appears "vague" even if the group has no record of making "opportunistic" claims, analysts said Saturday.

In a statement via its Amaq news service, IS said one of its "soldiers" carried out Thursday night's attack which killed 84 people.

The act was "in response to calls to target nations of coalition states that are fighting (IS)," said the statement.

The claim "is vague and does not allow us to know if the attack was commanded or only inspired by IS calls to hit France," said Yves Trotignon, former analyst with French anti-terrorist service DGSE.

David Thomson, specialist in jihadi groups and author of a book on French jihadists, noted the group usually distinguishes between "soldiers" and "sympathisers" in claims of responsibility.

Two years ago, IS spokesman Abou Mohammed Al-Adnani called on sympathisers in western nations to kill "disbelieving" Americans or Europeans ?- "especially the spiteful and filthy French" and citizens of other countries fighting the organisation.

Syrian-born Al-Adnani urged supporters to kill the enemy "in any manner" including "run him over with your car."

- 'Never' a wrong call -

Thomson said that even if IS had not necessarily directly commanded the attack, the group had never been found to make a false claim to date.

Thomson noted that "several times they have had the possibility of claiming an attack they were not behind -- for example, the Egyptair crash" in May.

"But they didn't do so, even as Egyptian authorities suggested Islamic extremists were to blame."

Thomson also highlighted IS reactions to other previous claims.

In cases "initiated by their propaganda, a clear claim did not necessarily follow.

"For example, after the attack at San Bernardino" California in December, when a Muslim couple killed 14, IS reacted by "congratulating" the perpetrators of killings it said were carried out by "sympathisers".

Thomson added: "When a claim is made, in most cases the statement is followed by elements of proof -- photos or videos allowing the establishment of a link between the terrorist and the organisation" of the attack.

For Thomson the Nice attack "could be similar to that of Magnanville," the stabbing to death of a senior police officer and his companion at their home west of Paris last month by a man who claimed IS allegiance.

Self-claimed jihadist Larossi Abballa had "minutes before his act asked his Facebook contacts to tip-off IS's media branches."

The group thereafter saluted the murders by "a soldier of Islamic State."

Although Nice killer Mohamed Lahouaiej-Bouhlel was not known to intelligence services and appears to have undergone rapid radicalisation his profile "does not rule out his being a jihadist," Thomson concluded.