Polish officials say a high-ranking army officer and a civilian have been detained on suspicion that they spied for a hostile foreign intelligence service.

Polish media reported that the two are suspected of spying for Russia, but prosecutors have refused to identify the country in question.

Prosecutor General Andrzej Seremet said Thursday that the matter is of an "extremely sensitive nature." He promised more information in the coming days.

Seremet said that the two were detained after months of investigation and that they are suspected of "hurting Poland's interests."

Defense Minister Tomasz Siemoniak said several army members suspected of drug smuggling were also detained. He called it "an important day in the fight for the purity of the Polish army."