A Russian spy ship making its way along the Eastern Seaboard has been spotted just south of a major submarine base in Connecticut, a report said Wednesday.

The ship, the SSV-175 Viktor Leonov, was located about 30 miles south of Groton, Conn., but still in international waters, Fox News reported.

A US official said the Russian ship was “loitering” in the Atlantic, according to the report.

The Naval Submarine Base New London, the main US Navy submarine base on the East Coast, is in Groton. It is home to 15 attack submarines.

The Leonov, which last sailed near the US in April 2015, is capable of intercepting communications and also measuring US Navy sonar capabilities.

It is armed with surface-to-air missiles.

The proximity of the spy ship is another in a series of military provocations by the Russians in recent days, as the Trump administration has been besieged by questions about its relationships with President Vladimir Putin and his Kremlin associates. National security adviser Michael Flynn resigned this week over his inappropriate contact with Russian officials.

Last Friday, four Russian fighter jets buzzed a Navy destroyer in the Black Sea, coming as close as 200 yards to the USS Porter.

Moscow also deployed a ground-launched cruise missile inside the country in December, a development that could violate terms of a Cold War-era arms control treaty with the US.