UK police have launched a terror investigation after bombs were sent to three London-area transit hubs.

Officials found packages containing explosives at Heathrow Airport, London City Airport and the Waterloo Station train hub, London’s Metropolitan Police said.

“These devices, at this early stage of the investigation, appear capable of igniting an initially small fire when opened,” police said in a statement.

All three devices were sent in the same padded mail packaging, and officials are investigating the incidents as a single case, cops said.

The first package was found at The Compass Centre on Heathrow’s campus at 9:55 a.m. — about 1,000 feet from the tarmac. The building was evacuated, but neither airport terminals nor flights were affected, police said.

A second device was discovered in a post room at Waterloo around 11:40 a.m., and the area was cordoned off.

The third turned up inside City Aviation House at London City Airport around 12:20 p.m., prompting the evacuation of that building, as well as temporary suspension of an air tram.

None of the devices was triggered, and no injuries have been reported.