The UK Ministry of Defence has publicly expressed concerns after a RAF plane with Defence Secretary Grant Shapps was subjected to GPS jamming while flying near the Russian exclave of Kaliningrad. While London did not explicitly assign blame for the incident, British media reports are claiming Moscow was behind it.

The incident was publicized by the ministry on Thursday, with a spokesperson revealing the electronic interference had occurred while Shapps was traveling back to the UK from Poland on Wednesday.

“The plane carrying the defence secretary and his delegation temporarily experienced GPS jamming when they flew close to Kaliningrad,” the spokesperson said.

“It didn’t threaten the safety of the aircraft and it is not unusual for aircraft to experience GPS jamming near Kaliningrad, which is, of course, Russian territory,” the official added.

While the ministry did not overtly attach any blame for the incident on Russia, government sources told the British media that this was likely the case. No actual evidence to back up such allegations, however, has been presented.

“While the RAF are well prepared to deal with this, it still puts an unnecessary risk on civilian aircraft and could potentially endanger people’s lives. There is no excuse for this, and it’s wildly irresponsible on Russia’s part,” an unnamed defense source told The Times.

Over the past few weeks, GPS connectivity issues have been repeatedly been reported in the vicinity of Kaliningrad, including in Poland as well as in the wider Baltic region, with the issue reaching southern Swedish and northeastern German regions.

While multiple media reports attributed the interference to Russian electronic warfare jammers allegedly getting activated in Kaliningrad, the troubles also correspond with the ongoing military maneuvers of the US-led NATO bloc in the area, said to be the largest exercise staged since the end of the Cold War era. Neither of the suspected parties who might have been causing the GPS interference has provided any public comment on the matter.