Counter-terror police are investigating three packages containing explosives found at Heathrow Airport, London City Airport and Waterloo station.

The « small improvised explosive devices » were found in A4 postal bags, the Metropolitan Police said.

The Met’s Counter Terrorism Command is treating it as a « linked series » and « keeping an open mind regarding motives ». No-one has been hurt, the force added.

The Compass Centre in Heathrow’s grounds was evacuated after a package was reported to police at about 09:55 GMT.

The package has since been « made safe », the Met said.

A Heathrow spokeswoman said the airport would assist the police investigation into the « criminal act ».

Two more packages were found in the capital during the next three hours. An area of Waterloo station was cordoned off after a second package was reported at about 11:40. British Transport Police said the item was « being assessed by specialist teams ».

Staff members were then evacuated from City Aviation House at City Airport in Newham after a third package was reported at about 12:10.

Specialist officers are at the scene and inquiries are ongoing, the Met said.

No flights or trains are believed to have been affected.