Following the terrorist attack on a District Line tube train at Parsons Green on Friday morning the police have appealed for help from the public.
Assistant Commission Mark Rowley, head of National Counter Terrorism Policing, said: “Our investigation is continuing at speed and our priority is to identify, locate and arrest those responsible.
“Hundreds of police officers are pursuing numerous lines of enquiry, trawling through hours of CCTV footage and speaking to witnesses.
“The device and remnants left at the scene have been taken away and are being examined by forensic experts. While this work is ongoing, there is no doubt in my mind that those responsible intended to cause great harm and injury.”
So far, detectives have spoken to 45 witnesses and continue to receive information from the public to the confidential anti-terrorist hotline.
The public has sent 77 images and videos to investigators via the UK Police Image Appeal website.
AC Rowley, continued: “My thoughts are with all those who have been affected by this terrible attack. It is an attack on all of us.
“I urge communities across the UK to be vigilant and report any suspicious behaviour to the police immediately. Please do not hesitate, no matter how insignificant you may think the information you have is – please let us decide. It could be crucial.”
Anyone with information is urged to call the Anti-Terrorist Hotline on 0800 789 321 or, in an emergency, always call 999.
Anyone with footage or images from the incident is urged to upload them at www.ukpoliceimageappeal.co.uk where they will be looked at by investigators.
The independent Joint Terrorism Analysis Centre has raised the threat level from international terrorism to critical. This means that their assessment is not only that a terrorist attack is highly likely but that a further attack may be imminent.
Military personnel have been drafted in to protect national infrastructure sites, allowing additional armed police officers to carry out patrols.
Communities across the UK can expect to see more officers, both armed and unarmed, on patrol by foot and in vehicles over the weekend. In particular, they will be patrolling at crowded places, iconic sites, transport hubs and ports.
This may mean disruption for those who are travelling. The public are asked to be patient and plan ahead, allowing time for delays.
Police are reviewing the security of events across the UK and working with businesses and organisers to make events as secure as possible. Security checks at events will be enhanced, so people attending events should arrive early and allow extra time for these checks. If you don’t need to take a bag, don’t take it.