MARSEILLE // Police in at least four European countries have been alerted to a backfiring ISIL propaganda stunt in which sympathisers based in the West were apparently urged to show their allegiance in social media posts.

The use of handwritten messages photographed against mostly European backdrops, intended to demonstrate the strength of support for ISIL in Europe and elsewhere, has enabled the discovery of the precise or likely locations in which these images were taken.

Hands or parts of hands were visible in some of the photographs – each of which showed a pro-ISIL message written in Arabic. But while no one revealed his or her face, specific streets and even apartment blocks were pinpointed with relative ease by readers of a citizen journalism platform, Bellingcat.com, and other websites, using basic internet search tools.

ISIL’s initiative, launched on Saturday, was intended as a social media coup ahead of a statement from its Syrian spokesman, Abu Mohammed Al Adnani.

Sympathisers who posted photographs were among thousands of supporters, also known as the extremists’ “fanboys”, who took to Twitter and Telegram – an instant messaging service long favoured by ISIL – in an attempt to drum up interest for the statement.

“In the event, the speech ISIL was trying to promote turned out to be a damp squib,” said Bellingcat’s co-founder, Eliot Higgins, a visiting fellow at King’s College, London. While urging “lone wolf” terrorist attacks in the West during Ramadan, Al Adnani appeared to accept the possibility of ISlL being driven from its Raqqa and Mosul strongholds, arguing that this would not amount to defeat since “defeat is the loss of will and the desire to fight”.

But, Mr Higgins added, “it was interesting that ISIS should be trying to build up a head of steam with a hashtag campaign after a period of being quiet on social media”.

He said it was impossible to be sure without further inquiry whether those who posted messages of support represent a genuine danger to public safety, or are merely passive admirers of the extremists. But it was “essential” authorities took the activities seriously, he added.

Mr Higgins said his platform co-operated with police services and that images posted in France, the UK, the Netherlands and Germany were now being investigated in those countries. Bellingcat readers also republished pro-ISIL messages photographed in a shop in Stockholm and at an unknown location in Turkey, along with photos taken by ISIL sympathisers beyond Europe’s borders, including from inside a Saudi Arabian oil refinery and somewhere in the United States.

Concentrating initially on a few Twitter postings, Bellingcat’s counter-campaign quickly led to locations being determined.

One photograph had been taken from a bus stop near the Bruce Grove underground station in north London, as revealed by scrutiny of clues including a double-decker bus and a station sign. “The area will be full of CCTV cameras and the footage should help the police,” Mr Higgins said.

@EliotHiggins the London photo is taken near a station in North London called Bruce Grove pic.twitter.com/zERFWmnMWj — Bondok (@mamzbondok) May 21, 2016

Another was traced to an intersection in a northern suburb of the German city of Münster. One Twitter user was able to work out where the photograph was taken from a map showing all of the city’s advertising pillars, including one pictured in the photograph.

The ISIL supporter in the Netherlands attempted but failed to conceal his or her location by mentioning Amsterdam in the message.

“Many Twitter users suggested it could possibly be in Amsterdam’s southern suburbs, given the many trees and its wide bike paths,” Bellingcat said of the ensuing search.

Things became clearer after a popular Dutch video and photo sharing site asked its subscribers to join the hunt. “Some went as far as comparing lamp posts in different areas of Amsterdam,” Bellingcat said, “while others suggested it might be in other, surrounding towns. This turned out to be correct, as a member of the Bellingcat investigative team was able to find the exact location in Hoofddorp, a town near Amsterdam Schiphol Airport”.

ISIS Fanboy number 4 geolocated in Holland, thanks to the many of you that helped https://t.co/ZjUBXaSxIR pic.twitter.com/XW5i0p7cjA — Eliot Higgins (@EliotHiggins) May 21, 2016

A balcony in a seven-storey block of flats was identified by freelance photographer Fredrik Naumann as the spot from which the picture was taken. When another Twitter user pointed out that the information still fell short of establishing which balcony, he replied: “It certainly has narrowed down the number of doors to knock and phones to tap for local law enforcement.”

In France, Twitter users soon worked out that one photograph had been taken on the Rue Championnat in the 18th arrondissement – or district – of Paris. The picture showed a Suzuki dealership, a “dead giveaway” according to Bellingcat since the company has only about six such outlets in the French capital.

“It was no great challenge to work out where these photos were taken,” Mr Higgins said. “[The] way this campaign backfired shows they (ISIL) are not as smart as people think. Yes, they make fancy videos and try to give the impression they are super-competent whereas they actually make stupid mistakes all the time.”

“I would certainly hope the police now act on the information, especially in Paris given what happened in that city only last November.

London’s Metropolitan Police told The National on Thursday it was “aware of social media activity” but that no arrests had been made.

“Enquiries are ongoing,” it added. A spokeswoman urged anyone who comes across “extremist or terrorist” material online to report it at www.gov.uk/report-terrorism.

There has been little other official comment, though Dutch media reported that police inquiries had begun in the Netherlands.

Alexandre Mendel, a French writer specialising in extremism and the author of a new book called La France Jihadiste, said: “I have no doubt the information revealed by this should be taken seriously.”

He said Bellingcat’s work had revealed an interesting area of inquiry for the authorities, but added: “It doesn’t mean these people are actually planning to be terrorists now or in the future, but confirms what the intelligence agencies believe.”

“In France, it’s estimated there may be 10-15,000 people who support Daesh, of whom as many as 3,000 may be at least susceptible in terms of being willing to put words and thoughts into action. Each terrorist cell typically has 50 members helping in all sorts of ways.”

foreign.desk@thenational.ae