Air traffic at Caen airport in France was halted on Friday morning after a bomb threat, authorities have said.
A bomb disposal squad has already been called in to deal with the situation.
"The interdepartmental demining service is on site on the runway and in the airport buildings,” the local prefecture said.
The airport, located in Normandy, is currently closed and travellers are advised to wait for updates.
Who is behind France’s latest airport bomb threat?
Authorities say a group of people broke onto the tarmac overnight, though the reason for their actions is not yet clear.
News site France 3 Normandie reported on its website that it had received an anonymous letter signed by "French environmental activists" during the night.
The letter claims activists broke into the airport premises and planted explosives to "denounce the environmental absurdity" of air transport.
"Explosives have been laid around the tarmac and will be detonated at 12 pm. We leave it to you to inform the police and airport management so that the damage is only material," states the letter, quoted by France 3 Normandie.
“Instead of reducing air travel, the authorities prefer to expand airports,” it continued.
Caen airport closed after bomb threat
"Air traffic is interrupted. Travellers are invited to consult the traffic situation before going to the airport," the prefecture posted on X, formerly known as Twitter, at 8 am on Friday.
According to local media, firefighters and bomb disposal experts had been inspecting the airport's facilities since early morning, while police officers were blocking access to the airport for arriving travellers.
Flights are currently suspended until 12.30 pm. Travellers who arrived at the airport this morning have been waiting in the parking lot.
The local municipality has also allocated a room in the town centre where passengers can wait in the warmth.
“The authorities are applying their procedures. For the moment, we have no deadline,” airport director Maryline Haize-Hagron told France 3 Normandie.
A flight from Marseille which was due to land at 8:25 a.m. was diverted to Rennes, where a bus will take passengers to Caen.