U.S. Coast Guard Sector Charleston has issued a marine safety bulletin warning mariners that a Russian spy ship is behaving badly off the coast of Georgia and the Carolinas.

“The United States Coast Guard has received reports indicating that the RFN Viktor Leonov (AGI-175) has been operating in an unsafe manner off the coast of South Carolina and Georgia. This unsafe operation includes not energizing running lights while in reduced visibility conditions, not responding to hails by commercial vessels attempting to coordinate safe passage and other erratic movements,” the bulletin said.

“Vessels transiting these waters should maintain a sharp lookout and use extreme caution when navigating in proximity to this vessel. Mariners should make reports of any unsafe situations to the United States Coast Guard.” 

A defense official told CNN that the USS Mahan, an Arleigh Burke-class destroyer, was shadowing the Russian ship.

The Viktor Leonov regularly patrols in international waters along the eastern coast of the US, having done so every year since 2015. According to the CNN report, the Russian vessel also routinely operates in the Caribbean, including Cuba and Trinidad and Tobago.