Bloomberg News reported Monday that Russian attack subs have carried out missions in the Irish Sea two times since the invasion of Ukraine in 2022, citing sources familiar with the issue.

Reports indicate that the first deployment of the Russian Kilo class submarine near the Irish Sea took place around 18 months ago, while the second occurred more recently.

It said that the extent of submarine movements was beyond anything British officials had seen before.

The report cited two sources familiar with the issue to say that U.S. officials knew about the sub-movements.

The White House, the British Foreign Ministry, Russia's Defense ministry, Ireland's defence ministry and Ireland's Defence ministry did not respond immediately to requests for comment.

Bloomberg reported that the Kilo-class sub is a diesel/electric attack submarine, capable of firing Russian Kalibr cruise-missiles as well as torpedoes or naval mines.

In 2022, Russia's navy will stage a series of large-scale exercises that will involve all of its fleets from Pacific to Atlantic. This is the latest in a long line of military confrontations with the West.

Simon Coveney, the Irish Foreign Minister at the time, said that they weren't welcome. (Reporting and editing by Stephen Coates in Bengaluru, with Devika Nair reporting from Bengaluru)