Hamburg Airport has been completely shut down after a bomb was found nearby.
Officials made the decision to stop all flights after the WWII explosive was unconvered.
A statement on the airport's website reads: "Due to a finding of a WW2 bomb in Hamburg-Schnelsen the airport is currently closed. No flights are departing or landing.
"The expected duration is still undetermined. All travelers should stay in contact with their booked airlines."
Passengers have been stuck aboard planes as pilots are told to keep the aircraft on the tarmac.
Have you been caught up in the events at Hamburg Airport? Email webnews@trinitymirror.com
One man stuck on a plane told Mirror Online how the pilot had told those aboard about the situation shortly before they were due to take off.
"We were meant to depart at 7.55pm," he said.
"We have just got of plane to go back to airport. People are relaxed.
"There is not much information on whats going on and how long (it will take before flights resume)."
While searching for unexploded ordnance from the Second World War, workers in Hamburg-Schnelsen found the 1000lb (450kg) bomb.
It is upside down with its tip up, a fire brigade spokesman told the German Press Agency, meaning it is unclear what kind of detonation device it is attached to.
Hamburg Airport is the fifth busiest in Germany measured by the number of passengers that travel through it.
In 2018 17,231,687 passengers and 156,388 aircraft used its facilities.
