Counterterror officers are investigating the three incidents as “linked” after all the packages – A4-sized white postal bags containing yellow Jiffy bags – were assessed to be small improvised explosive devices (IEDs).
One of the packages opened by staff at Heathrow caught fire, but no one was injured.
Neither of the devices found at Waterloo and London City Airport ignited, but workers at the airport’s Aviation House were evacuated as a precaution.
Irish police said they were “assisting the Metropolitan Police with their enquiries” after photos of the packages appeared to show Republic of Ireland stamps.
Scotland Yard has not ruled out the existence of other bombs, and issued advice to people travelling across London to be “vigilant” and report any suspicious packages.
Here's how the day unfolded:
Welcome to The Independent’s live coverage of the security alerts at three London locations – Waterloo Station, Heathrow Airport and London City Airport.
Counterterror officers are investigating three devices found earlier on Tuesday.
Here’s Lizzie Dearden with more:
The Metropolitan Police says investigators are "keeping an open mind regarding motives" at this stage.
London City Airport said in a statement: “We can confirm that City Aviation House has reopened and staff have returned safely, following the evacuation of approximately 100 staff at 12.15pm due to the discovery of a small improvised explosive device.
“Specialist police officers dealt with the device, which did not affect flight operations. The airport terminal remained open throughout. Inquiries by the Metropolitan Police are ongoing.”
Aviation House is where some airport staff work and is a two-minute walk from the passenger terminal. The building was reopened shortly before 4pm.
Mayor of London Sadiq Khan has thanked police, security and transport officials.
Sky News correspondent Alistair Bunkall posted a picture to Twitter which he claimed showed the packages sent to Heathrow airport and Waterloo station.
One of the images showed a partially-burned package addressed to the airport, which he said had caught fire.
A travel update following today’s security alerts. Rush hour has continued unhindered at Waterloo railway station with trains running as normal.
A small group of police officers have remained behind the cordon near the Network Rail office where the package was believed to have been found.
No flights or passengers at Heathrow or City airports were affected. DLR services to London City Airport were briefly suspended but are now fully operational.
Police in the Republic of Ireland have confirmed they have been asked to assist the Metropolitan Police after Irish post stamps were seen on the packages.
A spokesperson for the Gardai said: “We are assisting the Metropolitan Police with their inquiries.”
More from our Home Affairs Correspondent Lizzie Dearden on the stamps seen on images of the packages sent today.
The British Transport Police (BTP) have released a statement. “Understandably the discovery of these items may cause concern, however I would like to offer some reassurance to those passengers intending to travel this evening,” said BTP assistant chief constable Sean O’Callaghan.
“We will have a number of specially trained officers on duty to keep commuters safe and reassured. Officers will be highly visible on station concourses, on board trains as well as the London Underground network. If you have any concerns, please speak with us or indeed a member or rail staff.
“Passengers are of course the eyes and ears of the network and we want to hear from you if you see something that doesn’t look right. You can report something by discreetly sending us a text to 61016, or by calling 0800 40 50 40.”
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