A passenger jet approaching Heathrow Airport was involved in a near-miss incident with two drones, the first such recorded instance in the UK.
Scotland Yard was informed after the incident in November last year, but the drones' operators have not been found, a report by the UK Airprox Board (UKAB) said this week.
The UK's Civil Aviation Authority (CAA) said it was the first time a near-miss incident involving more than one drone.
The incident occurred over east London as an Airbus A320 was approaching Heathrow Airport on November 20 last year.
The UKAB report concluded that the incident had "compromised the safety of