Mayor of London statements - terrorist attack at Parsons Green

Thanks to the dedicated work of our police officers and intelligence services, the UK's threat level has now been lowered from 'critical' to 'severe'. This means an attack is no longer thought to be imminent but is still highly likely.

Throughout the weekend, a thorough investigation has led to two arrests in connection with the cowardly terrorist attack at Parsons Green station.

On behalf of all Londoners, I would like to thank the Metropolitan Police, British Transport Police and the security services for leaving no stone unturned in the ongoing investigation to track down those responsible, and for doing everything possible to keep us all safe.

I would urge all Londoners to remain vigilant over the days ahead. You will see more police - including armed officers - on the streets and transport network throughout the week. They are there to keep us safe.

London's response to this attack shows once again that we will never be intimidated by terrorism.

This morning police have made a significant arrest as part of the investigation into the terrorist attack at Parsons Green station yesterday morning.

An 18-year-old man was arrested in Dover under section 41 of the Terrorism Act.

The police investigation is ongoing and there will still be significant activity today and over the days ahead. I am sure I speak for London when I say we are incredibly grateful to the police and intelligence services for doing everything possible to keep Londoners safe.

I would urge anyone with any information at all relating to the investigation to call the Anti-Terrorist Hotline on 0800 789 321, to help the police with their extremely difficult job. In an emergency, always call 999. If you see anything suspicious, please report it.

It is important we all remain alert and vigilant. There will be an increased police presence across London today and over this weekend, including additional armed officers. They are there to keep us safe.

London will never be intimidated by terrorism. We will always defeat those who seek to harm us and destroy our way of life.

The national threat level has now been raised to 'critical' after the evil and cowardly terrorist attack at Parsons Green. As the Prime Minister has said, this is our highest level of security preparedness.

I utterly condemn the hideous individuals who target innocent people and attempt to use terror to harm us and destroy our way of life.

Please remain vigilant. If anybody knows anything at all about who might be responsible for this attack, they should contact the police immediately. The Anti-Terrorist Hotline is 0800 789 321.

Everything possible is being done to protect our city and keep us all safe, both Londoners and visitors to the capital. I attended the COBRA security meeting this afternoon and am in contact with the Metropolitan Police and other emergency services who are leading the response and investigation.

Rest assured the full resources of our police and security services are being deployed to track down those responsible. They will be caught and brought to justice.

Tonight and this weekend there will be additional police officers – including armed officers – on our streets to keep us safe. There will also be some military personnel deployed to guard sensitive sites which are closed to the public.

Meanwhile, on our transport network, extra staff will be on duty and visible.

London stands together today as always. We will never let those who seek to divide us win – we will never be intimidated or defeated by terrorism.

Following the cowardly terrorist attack this morning, I want to reassure all Londoners and visitors that we are doing everything possible to protect our city.

This afternoon, I attended the emergency COBRA meeting in Whitehall with the Prime Minister and I am in constant contact with the Metropolitan Police.

Parsons Green tube station remains closed and there is still a cordon around the station. The District Line will remain part-suspended with no service between Earl's Court and Wimbledon at least until the end of service today. Please check Transport for London's website for further travel updates.

The police investigation is still ongoing and I ask Londoners and visitors to our city to remain calm and vigilant. If you see anything suspicious, please report it to the police. The anti-terrorist hotline is 0800 789 321.

As many Londoners make their way home this evening, you may see more police officers on the streets and on our transport network. Please be assured that they are there to help keep you safe. There will also be extra TfL staff on hand to help passengers.

London stands together today as always. We will never let those who seek to divide us win – we will never be intimidated or defeated by terrorism.

The Metropolitan Police have confirmed that the explosion on a train at Parsons Green Station this morning is being treated as terrorism.

Our city utterly condemns the hideous individuals who attempt to use terror to harm us and destroy our way of life.

As London has proven again and again, we will never be intimidated or defeated by terrorism.

I am in close contact with the Metropolitan Police, Transport for London, Government and other emergency services who are responding at the scene and leading the investigation. I will be attending the emergency COBRA meeting in Whitehall this afternoon with the Prime Minister.

My sincere gratitude goes to all our courageous emergency responders and the TfL staff who were first on the scene.

I urge all Londoners to remain calm and vigilant, and to check tfl.gov.uk for travel advice.

For further updates or information please follow the Metropolitan Police on Twitter.