OSLO, March 5 (Xinhua) -- Norway's foreign intelligence service has named digital intelligence as the top threat to the Nordic country, public broadcaster NRK reported Monday.

Various subjects try to compromise and infiltrate Norwegian authorities and businesses, the Norwegian Intelligence Service (NIS) said in its annual threat assessment.

Academia, power and telecom companies and state institutions are exposed to persistent foreign intelligence activities, whose purpose is primarily to obtain information about traditional political and military goals, and secondly industrial espionage, NIS said.

The foreign intelligence agency also named a network attack against Norwegian health authorities as a proof that intelligence activity against Norway is not limited to traditional political and military goals.

"In the digital space, particularly three types of activities can be serious threats to Norway: influence, intelligence and sabotage," NIS said in the assessment report.

According to NIS, another significant threat lies in the fact that 40 foreign fighters with connection to Norway still remain in Syria and Iraq, where they "will be able to use the expertise they have gained through IS, despite the fact that IS is militarily defeated."