Tuesday, 19 September:
Detectives investigating the Parsons Green terrorist attack have arrested a man in Wales today, Tuesday, 19 September.
The 25-year-old man [C] was arrested under section 41 of the Terrorism Act at approximately 19:08hrs at an address in Newport.
The arrest was carried out by officers from the Met's Counter Terrorism Command, supported by colleagues from Gwent Police and the Welsh Extremism and Counter Terorrism Unit (WECTU).
A search is taking place at an address in the Newport following the arrest.
Two other men who were arrested on Saturday remain in police custody.
An 18-year-old man [A] was arrested by Kent Police in the port area of Dover at approximately 07:50hrs under section 41 of the Terrorism Act. A warrant for his further detention was granted by Westminster Magistrates' Court until 23 September.
A 21-year-old [B] was arrested in Hounslow at 23:50hrs under section 41 of the Terrorism Act. A warrant for his further detention was granted by Westminster Magistrates' Court until 21 September.
Searches at two addresses in Surrey and a commercial property in Hounslow are still ongoing and are expected to last some days. We would like to thank the public for their patience and cooperation.
Commander Dean Haydon, head of the Met Counter Terrorism Command, said: "This continues to be a fast-moving investigation. A significant amount of activity has taken place since the attack on Friday. We now have three men in custody and searches are continuing at four addresses. Detectives are carrying out extensive inquiries to determine the full facts behind the attack.
"We anticipate that the searches will take some days to complete and may cause further disruption. However it is important that we continue with these searches and I'd like to thank all those affected for their support, patience and cooperation."
He added: "As police and our partners do all we can to confront the threat, public vigilance remains as vital as ever.
"We urge the public report any suspicious activity to the police by calling us, in confidence, on 0800 789 321, or in an emergency by dialling 999.
"We are asking the public to look out for anything that seems out of place, unusual or just doesn't seem to fit in with day-to-day life. It may be nothing, but if you see or hear anything that could be terrorist-related trust your instincts, then ACT, and call us."
Monday, 18 September:
UPDATE: Two men arrested on Saturday, 16 September in connection with the investigation into the Parsons Green tube attack remain in police custody.
An 18-year-old man [A] was arrested by Kent Police in the port area of Dover at approximately 07:50hrs under section 41 of the Terrorism Act. A warrant for his further detention has been granted by Westminster Magistrates' Court until 23 September.
A 21-year-old [B] was arrested in Hounslow at 23:50hrs under section 41 of the Terrorism Act. A warrant for his further detention has been granted by Westminster Magistrates' Court until 21 September.
They both remain in custody at a south London police station.
Searches are continuing at two addresses in Surrey and a commercial property in Hounslow in connection with this ongoing investigation.
We would like to thank the public for their patience and cooperation.
Saturday, 17 September:
Assistant Commissioner Mark Rowley, National Lead for Counter Terrorism Policing provided an update on the Parsons Green Investigation and the threat level to the UK from international terrorism being reduced from critical to severe, he said:
"The high pace and rapid progress of this investigation is continuing. There was another arrest overnight and two men are in custody. There are now two searches continuing at addresses in Surrey and we are getting a greater understanding of the preparation of the device.
“There is still much more to do but this greater clarity and this progress has led JTAC – the independent body that assess threat – to come to the judgement that an attack is no longer imminent. And you will have heard consequently the Home Secretary’s announcement that the threat level has reduced from Critical to Severe which of course means that an attack is highly likely.
“Members of the public will be wondering what that means in terms of their travel into work tomorrow. For practical and precautionary reasons we made the decision that the increased resources will continue for the beginning of this week. So the public will still see that high level of policing presence; some armed, some unarmed.
“The military support we have had in place under Operation Temperer will start to phase out as we move through the coming week. There are detailed and well-rehearsed plans in place to ensure a smooth transition from Operation Temperer, and military personnel will remain at readiness to deploy in support of the police should future security situations require.
“I want to stress however, that specialist teams, well-rehearsed at dealing with major incidents, continue to provide a strong visible presence throughout the capital and across the UK.
“The last thing I would say to members of the public is that there is still a severe threat level. If you see something you are worried about or know somebody you are worried about don't hesitate, just ACT. Please call us on the Anti-Terrorism Hotline 0800 789 321 or report online by visiting www.gov.uk/ACT.”
A second man has been arrested by detectives from the Met's Counter Terrorism Command investigating the terrorist attack at Parsons Green on Friday, 15 September.
The 21-year-old man [B] was arrested in Hounslow at around 23:50hrs on Saturday, 16 September.
He was arrested under section 41 of the Terrorism Act and taken to a south London police station where he remains in custody.
A search is taking place at a residential address in Stanwell, Surrey, in connection with this arrest.
Anyone with footage or images from the incident at Parsons Green is asked to upload them at www.ukpoliceimageappeal.co.uk where they will be looked at by investigators.
Anyone with information is urged to call the Anti-Terrorist Hotline on 0800 789 321 or, in an emergency, always call 999.
Saturday, 16 September:
Statement on the ongoing investigation into the terrorist attack at Parsons Green by Senior National Co-ordinator for Counter Terrorism Policing, Neil Basu:
“I would like to update you on the ongoing investigation into the terrorist attack at Parsons Green Tube Station yesterday morning.
“The Metropolitan Police and its partners across the Counter Terrorism Policing Network have been working around the clock and through the night to identify, locate and arrest those responsible for this cowardly crime.
“At approximately 7.50am this morning, local police officers in Kent arrested an 18-year-old man in the departure area of the Port of Dover. He was arrested on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism. He has now been transferred to custody at a police station in London.
“Officers from Kent Police partially evacuated the Port of Dover at around 11.40am this morning. This was to enable them to search the premises as a precautionary measure. This work is now complete. They recovered a number of items during this search.
“A short while later, at around 1.40pm - with the assistance of Surrey Police - Met Police officers also evacuated a house in Sunbury-on-Thames. As a precautionary measure, we evacuated the surrounding buildings and set up cordons within a 100-metre radius.
“I want to reassure that community that our expert officers are quickly and thoroughly searching that address and working to ensure that it is safe. Once this is done a detailed search will take place.
“I would like to thank residents in Sunbury and people travelling in and out of the Port of Dover for their patience and understanding while officers carry out this precautionary but important work.
“Their support has enabled us to act swiftly.
“The police and Surrey Local Authority are working to support displaced residents and to get them back into their homes as soon as possible.
“At this stage we are keeping an open mind around whether more than one person is responsible for the attack and we are still pursuing numerous lines of enquiry and at a great pace.
“So what happens next? Our priorities are to ensure that the address in Sunbury is safe and to identify and locate any other potential suspects.
“We have identified 121 witnesses so far, and we have spoken to 100 of them already. Officers continue to trawl through many hours of closed circuit television footage and more than 180 videos and pictures that have been sent to them by the public. We continue to take large numbers of calls from the public via the confidential Anti Terrorist Hotline.
“The public’s help remains crucial, and I urge anyone with information, no matter how significant they think it is, to continue letting us know.
“Police officers across the UK are also still out in force, protecting communities.
“Yesterday the Prime Minister announced that the terrorism threat level had been raised to critical by the independent Joint Terrorism Analysis Centre, or JTAC. This means a terrorist attack is not only highly likely but a further attack may be imminent. The threat level remains at critical for the time being but is under constant review.
“Military personnel have been drafted in to protect national infrastructure sites, allowing additional armed police officers to carry out patrols. And we are very grateful for our military colleagues’ support.
“Communities across the UK will continue to see more officers, both armed and unarmed, on patrol by foot and in vehicles over the remainder of the weekend. In particular, they will be patrolling at crowded places, iconic sites, transport hubs and ports.
“In total, we know that 30 people have received treatment at hospital for injuries. We are incredibly grateful that no one was killed yesterday but my thoughts are with those people and everyone affected by this terrible and traumatic attack.
“I would like to finish by thanking the public for their support at this crucial time.
“The fact that so many communities stand together against the cowardice that is terrorism is a tremendous strength here in the UK.”
Police officers have evacuated and are searching a residential address in Sunbury, Surrey.
The evacuation is a precautionary measure following the arrest of a man in Dover, Kent, at approximately 07:50hrs this morning in connection with the investigation into the terrorist attack at Parsons Green Underground Station on Friday, 16 September.
Officers began evacuating the address at approximately 13:40hrs today.
Residents in the buildings immediately surrounding the address are also being evacuated as a precautionary measure.
Cordons are being put in place at a 100 metre radius to facilitate the Metropolitan Police Service’s operation, which is being supported by colleagues from Surrey Police.
A search of the address is ongoing and the cordons will remain in place until the operation is complete.
Police would like to thank the local residents directly affected for their cooperation and patience. Local officers are on duty in the immediate area to talk to the community and address any concerns that they may have.
No further arrests have been made.
Detectives investigating the terrorist attack at Parsons Green on Friday, 15 September have made an arrest in connection with the investigation.
The 18-year-old man was arrested by Kent Police in the port area of Dover this morning, Saturday, 16 September, under section 41 of the Terrorism Act.
The man remains in custody at a local police station. He will be transferred to a south London police station in due course.
Deputy Assistant Commissioner Neil Basu, Senior National Co-ordinator for Counter Terrorism Policing, said: “We have made a significant arrest in our investigation this morning. Although we are pleased with the progress made, this investigation continues and the threat level remains at critical.
“The public should remain vigilant as our staff, officers and partners continue to work through this complex investigation. We are not, at this time, changing our protective security measures and the steps taken to free up extra armed officers remain in place.
“This arrest will lead to more activity from our officers. For strong investigative reasons we will not give any more details on the man we arrested at this stage.”
Detectives from the Met's Counter Terrorism Command are continuing to urge anyone with information about the terrorist attack to contact police.
Thirty people are known to have been injured during the attack in which an improvised explosive device was detonated on a tube train at Parsons Green Underground Station at around 08:20hrs on Friday, 15 September.
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. 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.
Anyone with information is urged to call the Anti-Terrorist Hotline on 0800 789 321 or, in an emergency, always call 999.