The Russian Northern Fleet's anti-submarine force has detected a foreign submarine in the country's boundary waters and "expelled" it, Russian news agencies reported on Saturday, citing an unnamed spokesman for the Russian Navy Main Staff.
A foreign submarine, presumed to be a U.S. Navy Virginia-class vessel, was detected by Northern Fleet forces on duty in the Barents Sea on Aug. 7, the spokesman said.
A U.S. Defense official, speaking on condition of anonymity, could not confirm the incident and had no comment on the Russian claim.
"An anti-submarine attack group and an Ilyushin Il-38 anti-submarine aircraft were sent to the said area to search and track the sub," the Russian navy spokesman was quoted by Interfax news agency as saying.
"The Northern Fleet anti-submarine forces' active maneuvers expelled the submarine from the Russian Federation's boundary waters."
The report from Russia from could be the latest sign of increasing tensions between Moscow and Washington over the crisis in Ukraine.