Birmingham Airport says it is “slowly returning to normal” after its terminal was evacuated due to a suspicious vehicle.
Many flights were grounded and people were told to leave the airport building while the police operation began at around 12:20 BST.
An Explosive Ordnance Disposal (EOD) team searched the vehicle, which was “deemed safe”, West Midlands Police said.
An airport spokesman apologized for “any inconvenience and disruption” but said “the safety and security of everyone at the airport was our number one priority as we worked through this incident with police partners.”
The evacuation affected passengers checking in for flights, with a police cordon set up around the airport and people advised not to travel to the airport.
The BBC understands that passengers who passed security were allowed to move on to departures as they were deemed safe.
In its latest update, an airport spokesperson said: “Birmingham Airport is working closely with its airline partners to minimize any potential disruption to customers.
“Most of the flights that were on the ground have already taken off, with only one flight cancelled.
“Customers are still advised to check the status of their flight with their airline.
“Again, we apologize for the inconvenience to our passengers, but their safety and security is our priority.”
Travelers posted their frustration on social media at being left on planes that had just arrived at the airport.
One X user, @harmancheeta, said they were “stuck on a plane, claustrophobic, begging to get off” and asked: “How long is this going to take?”.
Another, @SpandleRandle, said his mum and dad were also on a plane at Birmingham Airport after returning from Spain and had “no idea what was going on”.
Some were not happy with the way he handled the outage.
Passenger Samia Khan said “there are no updates, no one is telling us what’s going on, it’s just absolutely ridiculous”.
“I could have easily just taken the train to Amsterdam and I’ll probably choose that next time because flying was so difficult with all the delays,” she said.
“Birmingham Airport could have handled the whole situation a lot better.”
Ian Pugh posted a photo of crowds outside the building.
“It looked very busy and the number of people just started to grow,” he said.
“At first I just thought people were going to the station and maybe the monorail had broken down, but the numbers just kept increasing.”
Some passengers were asked to gather at the nearby National Exhibition Center (NEC).
West Midlands Fire Service and West Midlands Ambulance Service had teams at the scene while the investigation took place.
Passengers were allowed back into the airport from 15:30 BST.
Birmingham Airport was was also evacuated in Septemberwhen passengers were temporarily asked to leave a small area in the arrivals area.