Alleged Russian interference targeting Ursula von der Leyen disabled GPS navigation services at a Bulgarian airport and forced the European Commission president's plane to land using paper maps.

The plane carrying von der Leyen to Plovdiv on Sunday (August 31) afternoon was deprived of electronic navigation aids as it approached the city's airport, with three officials familiar with the incident saying it was being treated as a Russian sabotage operation, according to the Financial Times (FT).

"The entire GPS system at the airport stopped working. It was an undeniable interference," one of the officials said.

After circling the airport for an hour, the pilot decided to land manually using analog maps, they added.

The Kremlin and the European Commission were asked for comment. The Bulgarian Air Traffic Control Service confirmed the incident in a statement to the FT.

"Since February 2022, there has been a significant increase in cases of jamming and, more recently, spoofing of GPS systems," the statement said.

"These interventions disrupt the accurate reception of GPS signals, leading to various operational challenges for aircraft and ground systems," it added.

So-called GPS jamming and spoofing, which disrupts or prevents access to the satellite navigation system, has traditionally been used by the military and intelligence services to protect sensitive sites, but is increasingly being used by countries such as Russia as a means of disrupting civilian life.

EU governments have warned that the increasing GPS jamming, for which Russia is blamed, risks causing a major air disaster by essentially blinding commercial aircraft during flight.

Incidents of GPS jamming have increased significantly in the Baltic Sea and Eastern European countries close to Russia in recent years, affecting aircraft, ships, and civilians who use the service for daily navigation.

Von der Leyen was flying from Warsaw to the central Bulgarian city to meet with the country's Prime Minister Rosen Zhelyazkov and visit an ammunition factory in Sopot.

The Commission president is on a tour of EU frontline states to discuss efforts to improve the bloc's defense readiness in response to Russia's war against Ukraine.

"Russian President Vladimir Putin has not changed and will not change," von der Leyen told reporters while in Bulgaria.

"He is a predator. He can only be restrained by strong deterrence," she added.

Bulgaria is one of the most important European suppliers of military equipment to Ukraine, initially from Soviet-era weapons in the first months of the war, and now from artillery and other products manufactured by the country's large defense industry.

Von der Leyen left Plovdiv on the same plane without incident after the end of the visit. | BGNES