Alive and a threat: 200 British jihadists might come home

As many as 200 British jihadists, who fought alongside Islamic State in Syria, are still believed to be alive and would pose a very significant threat if they ever returned home, according to the UK's most senior counter-terror police officer.

Scotland Yard assistant commissioner Neil Basu was speaking at the launch of a nationwide campaign of cinema adverts to raise awareness of the threat posed by overseas extremist groups and radicalised individuals back in the UK.

Mr Basu revealed police and security services had foiled 18 terror plots in the UK in less than two years and that around one in five tip-offs from the public yield important information.

The head of Scotland Yard's Counter-Terror Command said the risk posed by returning jihadists remained one of the country's most significant threats.

Mr Basu said: "Everyone who we know travelled, we keep as close an eye on as we possibly can and we know where they are and what they're doing."

But the bigger worry, he added, was around those who had yet to return.

He explained: "They know that when they come back, they're going to be on our radar and they're going to be potentially prosecuted.

"We're not seeing, at this time, a lot of people wanting to come back or actually travelling back, it's still a very small number. But you ask if we're still worried about it... absolutely, it's one of our main threats."

The assistant commissioner said the authorities know where some of the British foreign fighters are overseas, but others they don't.

Mr Basu said he was "incredibly grateful" that 2018 was spared the level of carnage of the previous year, when dozens of people were killed in attacks in London and Manchester.

However, he warned the "worst-case scenario" was public complacency, revealing that there had been a "dramatic" fall in the number of instances security-related information was reported to the police.

More than 31,000 pieces of information were passed to police in 2017, which more than halved to 13,093 in 2018.

In both years, just over a fifth of the information passed on was "very significant", meaning it directly led to the identification of a suspect or plot or was a small piece of the jigsaw that helped a plot be disrupted or criminal be prosecuted, Mr Basu said.

He added that part of the reason behind the fall could be the dominance of Brexit, which "undoubtedly" took up much attention last year, when there was very little terrorist activity compared with 2017.

However, he warned that although terrorist plots were being foiled, terrorist activity remained extremely high.

A record 700 terror investigations are ongoing - up from around 500 in 2017.

Mr Basu added: "We need communities to stand up and report changes in behaviour that they are seeing within their communities which might actually help us stop these things before they happen."

Four far-right radical extremist plots and 14 Islamist terror plots have been foiled by police and the security services since March 2017.

The latest anti-terror campaign will see a minute-long advert played in 120 UK cinemas.

The film shows a series of scenarios, such as a man stockpiling hazardous material and another buying weapons, before rewinding and zooming in on the danger.

It is estimated that close to five million cinemagoers will see the new advert, which authorities say is a vital part in raising public awareness about the continued severe threat of terrorism facing the UK.