Scotland Yard’s specialist police are investigating three suspect packages, at three separate key transport hubs across London.
Police officers were called to Heathrow Airport, Waterloo Station and London City Airport between 09.55 and 12.10 on Tuesday.
It is unclear at this stage if all three incedents are linked.
Police have confirmed a package found at Heathrow has been “made safe” and are still assessing London City Airport and Waterloo Station.
Scotland Yard said in a statement, “At approximately 09:55hrs police received a report of a suspicious package at The Compass Centre, Nelson Road, Hounslow at approx 09:55hrs.
“The building was evacuated as a precaution. Specialist officers attended and the package was made safe.
“At approximately 12.10hrs today, Tuesday, 5 March, police were called to a report of a suspicious package at offices at City Aviation House, Royal Docks, Newham.
“Staff were evacuated from the building. Specialist officers are at the scene.. Enquiries are ongoing.”
British Transport Police said, “British Transport Police were called to Waterloo station at 11.40am today following reports of a suspicious package.
“The item is currently being assessed by specialist teams. Cordons are in place however train services continue to operate as normal at this time.”
A spokewoman for Heathrow said, “Earlier today, police responded to reports of an incident in the Compass Centre. Police response teams and the emergency services attended quickly, enabling colleagues to evacuate safely without injury.
“Heathrow Airport remains operational, flights are not impacted and passengers are able to travel as normal. The police are treating this as a criminal act and we will be assisting with this investigation.”