(BBC) - A "near miss" between a passenger jet and a drone has prompted warnings about safe use of the hobby aircraft.
An Airbus A320's wing passed 6m (20ft) below a drone hovering at Heathrow, said the Civil Aviation Authority.
It said drone pilots would face prosecution if they put the safety of other aircraft at risk.
News about the mid-air encounter comes only days after a Lufthansa jet nearly collided with a drone on the approach to Warsaw's international airport.
The CAA said it had recorded six other incidents between May 2014 and March 2015 at airports around the UK in which drones and piloted craft almost collided.
"Drone users must understand that when taking to the skies they are entering one of the busiest areas of airspace in the world," said Tim Johnson, director of policy at the CAA, in a statement.
Drone owners must be aware of the rules and regulations surrounding the flying of their craft, he said.
