A Lufthansa plane with 108 passengers on board nearly collided with a drone as it approached Warsaw's main airport on Monday afternoon, the airline said on Tuesday, Reuters reported.
The drone came within 100 meters (330 feet) of the Embraer plane when the Munich to Warsaw flight was at a height of about 760 meters, the airline and the Polish Air Navigation Services Agency (PANSA) said.
Police are investigating, a PANSA spokesman said.
The plane landed safely at 1409 GMT, a Lufthansa spokeswoman said.
PANSA changed landing directions for other planes until the area was clear. However, police and military helicopters sent to the area did not spot the drone.
The incident was first reported by the Aviation Herald. It cited the pilots as telling air traffic controllers they "should take care of your airspace" and "it is really quite dangerous".
With the use of commercial drones for applications from filming to sports events and agriculture booming, the European Union is currently working on new regulations for drones to protect the safety and privacy of its citizens.
The regulations are due to be presented in the autumn as part of the European Commission's new aviation package.
Among the few member states with specific regulations, Germany in June introduced new rules that prevent the use of drones within 1.5 km of airport perimeter fences.
Anyone wishing to fly a drone beyond that exclusion zone and in controlled airspace must request permission from air traffic authorities and fly no higher than 50 meters, depending on the size of the aircraft.
Drones caused alarm in France earlier this year when several flights were spotted operating over sensitive sites in Paris.
Lufthansa CEO Carsten Spohr sees opportunities for the group in the field of commercial drones, saying last month Lufthansa's maintenance and pilot training units could provide expertise.