Polish security services are investigating a potential national security breach after thousands of officers and soldiers received calls from a mystery caller in Russia, according to a report Thursday from Russian news site Sputnik. While Poland is looking at the breach of security as a serious state issue, some are suggesting that the calls were merely part of a commercial calling scam that requires the recipient of the call to dial a premium rate number. 

"Someone in Russia" reportedly called 10,000 soldiers and military employees in Poland, the country's defense ministry told Nasz Dziennik, a privately-held Polish newspaper.

The level of alarm that military investigators have reacted with is likely in large part to due to the shifting political and military relationship between Russia and Poland. Moscow's annexation of Crimea in March 2014 and its involvement in the ongoing Ukraine conflict has left Eastern Europe and former soviet and communist nations in a state of fear. While Poland doesn't border mainland Russia, it does share a border with Moscow's Baltic exclave of Kaliningrad that harbors a large fleet of navy ships and where the country keeps some of its nuclear-capable ballistic missiles.

Furthermore, Poland is part of a NATO that has long protested Russia's involvement in Ukraine and more recently its incursions into Syria, where Moscow is disrupting a U.S.-led bombing campaign against the Islamic State group.  

Polish investigators have been trying to track the number, which it believes comes from a Russian cell network, and the source of the leaked military cell numbers that it hopes will help it to find out why mostly members of its armed forces were targeted.  

"This type of call also reached a certain number of subscribers unconnected with the military. All phones belong to the Plus network, which is operated by the Polkomtel company," the Nasz Dziennik report said.