At least 20 European passenger flights received bomb threats on Thursday, days after eight planes were grounded because of hoax warnings in what experts say is probably a co-ordinated campaign to disrupt air travel.
Police and anti-terror authorities were called to search aircraft in locations including London’s Heathrow and airports in Italy, Poland, France, Austria, Bulgaria, Romania and the Czech Republic, with a handful of services diverted after receiving threats while in mid-air.