Germany's Hanover airport suspended flights on Saturday after a man drove onto the apron area before police stopped his car and overpowered him, they said.
"Flight operations are currently suspended," Hanover police tweeted, adding that the man drove onto the apron area at about 3.40 p.m. (1440 GMT). "The investigation into the background (of the incident) continues."
German mass-selling daily Bild reported on its website that the man's car had Polish registration plates.
It said police were investigating whether he was disturbed, under the influence of drugs, wanted to commit an attack or had another reason for driving onto the apron area, where planes unload their passengers.
It was unclear how long flights at the airport would remain suspended.