Police said the pilot reported that he thought an object, apparently a drone, had struck the front of the aircraft. Flight 727, which was heading from Geneva to Heathrow, then landed safely in London this afternoon, a British Airways spokesperson told ABC News.
The plane "was fully examined by our engineers and it was cleared to operate its next flight," British Airways said.
No arrests have been made and aviation police based at Heathrow are investigating, police said.
"Safety and security are always our first priority and we will give the police every assistance with their investigation," the airline added.
The Civil Aviation Authority, which is responsible for British aviation safety, is aware of a the "possible incident with a drone at Heathrow today," a CAA spokesperson said.
"Safety is our first priority," the spokesperson said. "Anyone operating a drone must do so responsibly and observe all relevant rules and regulations. The rules for flying drones are designed to keep all airspace users safe. It is totally unacceptable to fly drones close to airports and anyone flouting the rules can face severe penalties including imprisonment."