The discovery of a suspect piece of luggage forced authorities to close Haugesund airport on the west coast of Norway for several hours on Saturday, police said.
The airport was reopened after the luggage, a backpack found in toilets, was discovered to be harmless by bomb disposal experts sent from Oslo.
The pack was found on Friday evening around 11:00 pm (2200 GMT) and after an initial enquiry police decided to close the airport in the early hours of Saturday, Haugesund police chief Edgar Mannes told AFP.
He did not say why the authorities had delayed in closing the airport, which reopened at 1335 GMT.
Mannes said, "The bomb group investigated the backpack and found the name of the owner. At the same time as investigations were underway, the family contacted Haugesund police to explain that they had forgotten their luggage in the toilets."
When the decision was taken to evacuate and close the airport, the last departing flight had already taken off, so passengers were only affected on Saturday morning.
Flights for Oslo, Las Palmas in Spain and Bremen in Germany were affected by the closure, the airport said.