Washington (CNN) A Russian spy-ship has returned to international waters off the southeastern coast of the United States and is operating in what two US officials told CNN is an "unsafe manner."

The Viktor Leonov, a Russian surveillance ship, has been sailing off the coast of South Carolina and Florida in the last few days, officials tell CNN, adding that the ship's actions were determined to be unsafe because it is not using running lights in low visibility weather and it is not responding to commercial vessels' attempts to communicate to avoid potential accidents.

The official said the Vishnya-class spy ship was also engaged in "other erratic maneuvers."

A spokesperson for the US Coast Guard confirmed to CNN that the Coast Guard was broadcasting a "Marine Safety Information Bulletin" to alert mariners in the area to the Russian ship's presence and its behavior.

"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.

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