THOUSANDS OF AIRLINE passengers have been stranded after flights at Greek airports were cancelled or delayed today as a result of a technical problem.

The issue knocked out airspace radio frequencies, the country’s civil aviation authority said, calling the outage “unprecedented”.

At Greece’s main airport, Eleftherios Venizelos in Athens, passengers were stuck in long queues as several domestic and international flights were delayed or grounded altogether, an AFP reporter saw.

The radio frequency loss was first reported around 7am Irish time.

According to the BBC, some departures have sine been allowed to resume, while inbound flights are still being told to return to their point of origin. Thessaloniki airport has closed entirely as a result of the outage. 

An Aer Lingus flight from Dublin to Athens this morning had to be diverted to Dubrovnik in Croatia as a result of the issue.

“No plane landed or took off for at least two hours,” said the press office at Athens airport, where 31.6 million passengers transited in the first 11 months of 2025.

For up to three hours, most aircraft headed for Greek airports were redirected to Turkey, according to Greek public television ERT. Air traffic had been resuming progressively since 11am, authorities said, however it has resulted in widespread delays.

Panagiotis Psarros, head of Greece’s air traffic controller union, called the incident “very serious” and blamed what he said was “obsolete” airport equipment.

With reporting from Cormac Fitzgerald