A Russian warship approached within 315 yards of a U.S. Navy warship in the eastern Mediterranean Sea earlier this month in what U.S. officials say was a series of unsafe maneuvers. The USS Gravely was in the Mediterranean on a routine patrol June 17 to provide protection for the aircraft carrier Harry S Truman as part of Operation Inherent Resolve to counter ISIS. It was approached by the Russian Neustrashimyy-class frigate, according to U.S. officials. The Russian vessel made repeated passes behind the Gravely within its wake. At one point, the Russian ship pointed toward the Truman, the officials said. The Gravely eventually accelerated speed and moved ahead, with the Russian ship still following it before breaking off. “As Gravely changed course and speed, the Neustrashimyy also changed course and speed. The maneuvering demonstrates that the Neustrashimyy was not in fact restricted in her ability to maneuver, and was thus intentionally displaying a false international signal,” a U.S. defense official said. The official said the Neustrashimyy had raised an international signal a ship displays when restricted in its ability to maneuver when she took position two nautical miles off Gravely’s starboard quarter. Then the Neustrashimyy repeatedly asked Gravely over radio to maintain a safe distance while the Neustrashimyy continued to maneuver to get closer to Gravely. The official added that the encounter lasted for more than an hour. U.S. officials say they have served noticed to Moscow protesting the incident as unsafe. The U.S. is also objecting to published statements from the defense ministry that claim it was the U.S. that engaged in unsafe seamanship. The Russian news agency RT posted a video of a portion of the encounter that the Pentagon says fails to show the Russian actions and improperly and incorrectly shows the Americans appear to be at fault. Pentagon officials say they had not been fully aware of the details of the June incident until the Russians this week began to discuss it in the media. The encounter comes after several aerial close calls between Russian jets and U.S. military assets earlier this year. In April, Russian jets in two separate incidents performed “barrel rolls” over U.S. Air Force aircraft, and earlier that month, two Russian jets flew closely to the U.S. Navy missile destroyer USS Donald Cook.