Terrorists are calling for attacks on UK hospitals and other “vulnerable places” during the coronavirus outbreak, a senior police officer has revealed.

Protective security advice is being distributed to NHS trusts by counterterror officers, amid warnings that extremists are exploiting the pandemic to radicalise new recruits.

The national coordinator for the Prevent counter-extremism programme told The Independent that Isis supporters were “encouraging people to target the places that appear most vulnerable”.

Chief Superintendent Nik Adams said jihadis were calling for attacks during lockdown in the hope that police and security services would be “distracted and overwhelmed”.

“We’re seeing the exploitation of the circumstances to encourage acts of violence,” he added.

“The reality is we’re very prepared for any such eventuality, and monitoring any literature being disseminated around the world.

“We are working closely with colleagues across the Five Eyes countries, with academics and community advisory networks to monitor how that information is playing out, and making sure that protective security advice is being adapted for the places that might be considered more vulnerable now.”

Isis had inspired attacks around the world by calling for supporters to launch massacres on “soft targets” including tourist attractions and transport hubs.

But with lockdown measures in force, hospitals have become some of the most crowded places in the country while previous targets are deserted.

Security advice, drawn up by the National Counter Terrorism Security Office, is routinely given to large venues, places of worship and other places that draw crowds.

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Hospitals have been attacked by terrorists and armed groups in several countries, such as the Isis-claimed massacre at a military hospital Kabul, Afghanistan, in 2017. Such attacks normally occur during ongoing conflicts.

“We are looking for evidence of people mobilising towards violence and taking on some of those narratives that are coming out of Isis propaganda,” Chief Superintendent Adams said.

He raised concerns that coronavirus conspiracy theories were being used as a “hook” by extremist groups to draw in new recruits.

The closure of schools, rising unemployment and extended lockdown measures mean that more people are spending time online, often alone, and could be more vulnerable to these tactics.

Ch Supt Adams said false claims linking 5G technology to the spread of coronavirus were being “monitored very closely” by counterterror police.

“It’s being pushed out by extreme right-wing groups as a hook to get people onto chat forums, where they can then talk about other hate-related conspiracy theories and draw people into their narratives,” he added.

“From that, they can pick up those individuals who are must vulnerable to encourage them, radicalise them and take them towards terrorism.”

Police are concerned about people made more vulnerable by mental health issues and other factors in their lives, who have seen contact with teachers, psychologists, social workers and substance abuse services fall away during the lockdown.

“We’re becoming more concerned not just about young people spending time online but the impact of isolation, and the changing risk picture,” Ch Supt Adams said.

“My fear is that people have got more opportunity to spend more time in closed echo chambers and online chat forums that reinforce the false narratives, hatred, fear and confusion that could have a radicalising effect.

“In the short term there is a lack of statutory services to spot those changes and intervene to protect people.”

Police are concerned about the impact of children spending more time online alone (Getty Images)

Referrals to Prevent over radicalisation fears have fallen since the start of lockdown, and the senior officer said he fears it “means people aren’t seeing some of those behavioural changes and they’re not reaching out for help”.

Ch Supt Adams added: “We are still effectively supporting the people we know about who are vulnerable to radicalisation, but the challenge is all those people out there who we don’t currently know about because of all those protections that are not in place.”

Of more than 5,700 people who were referred to Prevent in 2018-19, the largest group, 38 per cent, were individuals with a “mixed, unstable or unclear ideology” — followed by suspected Islamists and far right extremists on 24 per cent each.

The largest age group was children and young people aged 20 and under, and a third of referrals were from education workers who are bound to raise concerns formally under the controversial Prevent “duty”.

The government announced an independent review of the programme in January 2019 but it has been hit by controversy that saw the lead reviewer step down amid a legal challenge.

Only 4 per cent of people were flagged to Prevent last year by their friends and family or community members, and Ch Supt Adams appealed for support.

“Close friends and family who are still engaging with people at home and online can spot those changes in behaviour and language, the sense that someone is really buying into some of these narratives,” he said.

“They’re the ones that have the opportunity to reach out to us and get advice and help.”