Defense Minister John Healey said on Thursday that the UK tracked Russian submarines in the North Atlantic for a month, calling them a threat to British undersea cables and pipelines,

According Healey, the operation involved a Russian Akula-class attack submarine and two Russian submarines associated with Russia’s Main Directorate of Deep-Sea Research (GUGI).

Healey revealed a Royal Navy warship and a Royal Air Force P-8 were deployed to monitor all three submarines, after which the Akula-class submarine withdrew from the area, but, according to the secretary, the two submarines associated with the GUGI remain active in the area and are currently being monitored.