Several Irish media outlets reported receiving bomb threats on Friday as a wave of hoax alerts that had so far mainly targeted airlines continued across Europe, with more than a dozen new flights affected.
A host of commercial flights in Europe have been hit by false bomb threats this week, forcing the authorities to reroute some planes or escort civilian aircraft with fighter jets.
Authorities are scrambling to identify the sources of the threats. Some of the messages have come in emails signed by "fighters of the Male State", which matches the name of a far-right movement in Russia -- though AFP has not confirmed any link to the messages.
No explosives have been found in any of the incidents so far.
A new kind of target emerged on Friday as staff at several Irish media organisations were evacuated after bomb threats were emailed to newsrooms, according to reports.
Police were deployed to Ireland's national broadcaster RTE's headquarters in Dublin, where armed officers were reported at the scene following the hoaxes.
Staff were also evacuated from the offices of the Irish Independent newspaper, the Newstalk and Today FM radio stations, and Virgin Media television, according to reports.
"We don't yet know whether it's an individual behind this effort or some form of a co-ordinated effort," Ireland's deputy prime minister Simon Harris told Cork 96FM radio.
He said it was a "serious and evolving situation".
But he added: "I do want to assure the people of this country that this is an issue being taken very seriously by the gardai (police), by our security forces and our cyber experts."
New bomb threats meanwhile targeted multiple flights to and from Lisbon, Rome, Prague and Sofia on Friday, authorities said.
A Ryanair flight scheduled to depart from Lisbon for Rome was targeted with a threat while the plane scheduled to fly the route was still approaching the Portuguese capital on its way over from Italy.
And at least 11 flights were targeted in the Czech Republic and Bulgaria: Four flights arriving at Prague airport and five flights leaving Prague were threatened, as well as two flights to Sofia.
In Ireland, Newstalk host Claire Byrne said after returning to air on Friday that staff at the outlet had been told to leave their building, then "advised that we could return... and that that warning was a hoax".
Ireland is scheduled to host two days of high-profile European Union meetings in Dublin next week.
The threat comes after nearly 30 passenger flights were targeted across Europe on Thursday, including planes bound for London, Madrid and Copenhagen.
Many of the airliner threats have targeted low-cost carriers.
Portuguese police said in a statement that following the threat to the Ryanair flight on Friday, "the Special Police Unit (UEP) carried out a security inspection of the aircraft, without any explosive device or suspicious object being detected".
In the Czech Republic, the airport and 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 latest threats.
Czech police had already checked four planes following threats on Thursday.
Some previous hoax messages seen by AFP have contained misogynistic messages.
"We, fighters of the Male State, with our actions today will leave a mark in history. Your feminist regime will remember it forever. The explosion will occur in 60 minutes. Today your skies will turn red," said one sent to multiple email addresses for Sofia airport.
Birmingham Airport in central England confirmed receiving a similar message from a group identified as "Men's State".
The Russian group Male State was designated an "extremist" organisation by the country's courts in 2021.
But it then supported Russia's invasion of Ukraine in 2022. Experts say it is unclear whether it is connected to Russian authorities.