HELSINKI (REUTERS) - Finnair on Wednesday (March 9) said it had noticed interference with its planes' GPS signals near Russia's Kaliningrad enclave, while other aircraft reported similar problems near Finland's eastern border with Russia since Sunday, Finnish authorities said.
The interference began soon after Finland's President Sauli Niinisto met US counterpart Joe Biden in Washington on Saturday to discuss deepening defence ties between Finland and Nato due to Russia's attack on Ukraine.
Prime Minister Sanna Marin told Reuters on Wednesday she had no information about the source of the disturbances, nor about whether they originated in Russia, while the Foreign ministry said it was looking into the events.
"If they would be caused by outside influence, it would surely be said publicly," Marin said.
The Kremlin did not immediately reply to a request for comment about the reported interference.
Some of Finnair's Asian flights and most of its European ones go past Kaliningrad, which is sandwiched between Nato members Lithuania and Poland on the Baltic Sea's eastern coast, the company told Reuters.
"Our pilots have noticed interference in GPS near the Kaliningrad area in the past few days," a spokesperson for Finland's national carrier said in an email.
Some 10 aircraft have also reported unusual disturbances in GPS signals near Finland's eastern border with Russia since last Sunday, Finnish Transport and Communications Agency Traficom said on Tuesday.
Traficom said it had asked aviation authorities to alert aircraft pilots to the situation by issuing an official Notice to Airmen (NOTAM) notification. The disturbances were continuing, it said.
"Flying is still safe. Airlines have operational procedures for such situations if the GPS signal is lost," Traficom's director Jari Pontinen said in a statement.
Lithuanian airline Transaviabaltika told Reuters it had been forced to cancel 18 flights from Helsinki to Savonlinna in eastern Finland after the lack of GPS made it impossible to land because the airport does not have alternative navigation equipment.
"We have made three attempts to fly to Savonlinna. So far, we have not succeeded," Manager Rene Must from Transaviabaltika told Reuters.
Electromagnetic radiation from the sun and signal jamming are the only two reasons that could explain such long-lasting disturbances that affect several planes, Director Jukka Savolainen from HybridCoE, a pan-European organisation that seeks to counter hybrid threats, told Reuters.
"States can have systems to see where the jamming comes from if they happen to be turned on and in that direction," he said.