Russian submarines and spy ships are aggressively operating near the vital undersea cables that carry almost all global internet communications, raising concerns in America, reports Reuters.

The US intelligence officials feel that the Russians might be planning to attack those lines in times of tension or conflict, says the report.

U.S. Worries about Russian Ships near Critical Undersea Cables

From the North Sea to Northeast Asia and even in waters closer to U.S. shores, there is increased Russian activity along the known routes of cables that carry the lifeblood of global electronic communications and commerce.

The New York Times reported that US spies had noticed Russian submarines and spy ships acting suspiciously near cables in the North Sea, north-east Asia and off the American coast.

The issue goes beyond old Cold War worries that the Russians would tap into the cables — a task U.S. intelligence agencies also mastered decades ago.

The ultimate Russian hack on the United States could involve severing the fiber-optic cables at some of their hardest-to-access locations to halt the instant communications on which the West’s governments, economies and citizens have grown dependent.

About £6.5 trillion-worth of business deals are transacted across underwater cables every day. Officials added that the Russians could also be looking for secret military cables used by the US.

The Times said there was no evidence of cable cutting but that the concerns reflected increased wariness among U.S. and allied officials over growing Russian military activity around the world.

“It would be a concern to hear any country was tampering with communication cables; however, due to the classified nature of submarine operations, we do not discuss specifics,”U.S. Navy spokesman Commander William Marks told the Times.

The US Navy has a submarine, named after former President Jimmy Carter, which is believed to be capable of listening into the communications passing through underwater cables.