Four planes landed safely after bomb threats were made across Europe on Tuesday, among them two Warsaw-bound flights and a Scandinavian Airlines flight that departed from Copenhagen.

Polish officials said they had received bomb threats involving two Warsaw-bound flights, but the planes landed safely and no explosives were found. A Ryanair plane from Manchester made an emergency landing at Murcia in southern Spain, with no explosives found; a fourth flight, from Israel, was forced to land in Sofia, Bulgaria. The Scandinavian Airlines plane landed at Warsaw’s Chopin Airport, where a security inspection did not turn up any explosive devices, and the airport closed a landing strip but was able to continue operating. The Times of Israel treated the incidents as hoax threats that forced the temporary closure of an airport.