A bomb squad was called in to defuse the suspect object, which turned out to be harmless, after it was found at one of the parking garages at Landvetter Airport, near Gothenburg in western Sweden, at around 5pm on Sunday.
“We have not received any threats in connection to the incident,” regional police press spokesman Ulf Lörstad told the TT news agency late on Sunday.
He added that police had nonetheless launched an investigation into sabotage and threat.
The airport was cordoned off between 6pm and 7.30pm while the bomb squad investigated the object, sparking long delays for those passengers flying in and out of Gothenburg on Sunday evening.
Routes to and from Landvetter were shut as well, causing traffic to grind to a standstill on the busy road going past the airport.
“All in all about ten flights were affected by the incident. Some flights took off more or less on time and some waited for their passengers,” Swedavia Landvetter press officer Åsa Öhman told regional newspaper Göteborgs-Posten on Monday morning.
“The airlines look after passenger lists, so we don't yet know how many travellers were affected yesterday,” she said.
She added that all services were set to return to normal on Monday.
More than five million passengers travelled via Landvetter last year, Sweden's second-busiest airport after Stockholm's Arlanda.