Flights across Europe were subject to “hoax” bomb threats on Thursday for the second time this week, disrupting air travel in London, Dublin and Helsinki, among others. According to Reuters, at least 27 different flights were affected, some forced to land unexpectedly and others escorted by fighter jets. Aer Lingus, Finnair, Wizz Air and Polish airline LOT confirmed to CNBC that some of their flights were affected. It comes after seven passenger planes across Europe, two of them departing from the UK, were the subject of alleged bomb threats on Tuesday and were described as “malicious hoax threats” by the UK government. Finnair said two of its flights, one from Helsinki to Rome with 144 passengers and 7 crew members and another from Helsinki to Vienna with 177 passengers and six crew members, received “unfounded or false” bomb threats on Thursday, and that both flights landed safely and customers disembarked from the plane. This is what we know so far. Local authorities in Rome and Vienna inspected the two flights and found nothing out of the ordinary. “Unfortunately, air traffic is sometimes subject to threats, as we have seen this week, when other airlines in Europe have also faced false bomb threats,” Finnair said in a statement. “Threats are almost always unfounded.” Hungarian low-cost airline Wizz Air confirmed to CNBC that its flight from Milan’s Malpensa airport to Bucharest’s Otopeni airport, as well as another flight to Warsaw, were the subject of bomb threats on Thursday. The flight to Bucharest was approaching its final destination and landed safely when the threat in Otopeni was reported, and security checks subsequently cleared the plane. The Wizz Air flight to Warsaw was diverted. “This incident comes amid a series of similar bomb threats affecting several airlines across Europe in recent days,” Wizz Air told CNBC. “Wizz Air is not the only airline attacked, other companies also suffer threats resulting in flight diversions and security checks.” Irish airline Aer Lingus diverted its flight from Dublin to Rome towards Normandy on Thursday morning, while Polish airline LOT said two of its flights from Warsaw received security threats. Both were cleared after safety inspections, the airlines told CNBC. Air France CEO Ben Smith said none of its flights were affected, but the coordinated threats are unprecedented. “It’s unfortunate and we hope it doesn’t give consumers any reason to slow down or reduce their travel plans.” U.S. Transportation Secretary Sean Duffy told CNBC’s “Squawk Box” on Thursday that the incidents appeared to be “hoax attacks.” He added: “We take security very seriously, so if they see any problems in the airspace or threats in the airspace, we shut it down… and so, with all of our assets in the US government and our partners in Europe, we are tracking this together and working together to make sure that American airspace, the American traveler, is safe.”