Police are urging football fans to help them tackle terrorism by reporting any security concerns at matches.
The call was issued ahead of the start of the Premier League season on Friday night and forms part of efforts to encourage all members of the public to be “counter-terror citizens”.
But he cited the explosions outside the Stade de France in Paris in 2015 and the attack at Manchester Arena last year as evidence that such locations can be a terror target.
He said: “We know from what we’ve seen on the ground, and also from terrorist rhetoric, that they are interested in attacking crowded places generally, and that would include stadia.”
Nearly a quarter of a million sports event stewards have been issued with a short guide giving key advice to help protect crowds of spectators.
Mr Aldworth said: “A lot of places will have very overt security like dogs, they will have a policing presence outside, they will have a strong security and stewarding presence on the inside.
“But, importantly, there will be quite a lot of security measures that people won’t see. There will be some covert resources.”
The senior officer emphasised that fans have a role to play in successful security operations.
He said: “We want them to think about what they might do in the event of an attack and we want them to be really, really vigilant.
“And not to be inhibited about reporting stuff to us. If it’s trivial to you, it might be significant to us. Don’t worry about it – just tell us and leave it to us to sort it out.”
Counter-terror agencies have highlighted the importance of public awareness as they confront a threat seen as unprecedented, following five attacks last year.
Mr Aldworth said the latest campaign was a continuation of that message, adding: “This is a partnership between the police, the security services and the public.
“If any one of that tripartite group aren’t doing their job, we are much weaker for it. They all have a part to play.”
Bob Eastwood, security and operations adviser for the EFL, said: “The safety of all fans is football’s number one priority and we all have a role to play in doing everything we can to keep each other safe – police, officials and supporters.”
The police’s Know The Game Plan advice says fans should:
– Arive early, allowing more time for security checks;
– Minimise what they carry as fewer bag searches will speed up entry;
– Be vigilant at all times and report anything suspicious to a steward immediately;
– Call 999 if they see anything that could pose an immediate threat to safety;
– Follow public address instructions in an emergency; if told to evacuate, do so immediately and do not wait around to film events on mobile phones;
– Move right away from the stadium as quickly as possible;
– Follow the local police force on Twitter for updates once safe.
