Europe flight bomb scares continue as 11 flights targeted in Prague and Sofia

New bomb threats have targeted multiple flights to and from Prague and Sofia, authorities said on Friday, as flights across Europe have been hit by hoax alerts this week.

Four flights arriving at Prague airport and five flights leaving Prague were targeted by new bomb threats on Friday, airport spokeswoman Denisa Hejtmankova told AFP.

"The threats concern incoming flights from Denmark, Great Britain and two from Spain. As for outgoing flights, it's flights to the Netherlands, Cyprus, Romania, Italy and Great Britain," she said.

The airport and Czech police declined to give details on the affected flights.

Prague airport spokesman Jiri Hannich told AFP that "airport operation remains standard and smooth" despite the threats.

Czech police already checked four planes following threats on Thursday.

A Bulgarian transport ministry spokeswoman told AFP alerts were also received for two flights to Sofia on Friday, and that both flights coming in from London Stansted Airport in Britain and from Brussels landed safely.

The Portuguese police said a Ryanair flight scheduled to depart from Lisbon for Rome on Friday was targeted as well.

Dozens of commercial flights in Europe have already been targeted by false alarms this week, forcing the authorities to reroute some planes or escort civilian aircraft with fighter jets.