The core of the Russian navy's Northern Fleet has been observed manoeuvring in and around Irish-controlled waters in recent days, ahead of planned live-fire drills.
The ships are being shadowed by the UK, US and French navies, as well as RAF combat aircraft, according to photographs and video released by the Defence Forces
Irish Air Corps aircraft and Naval Service vessels made the observations as part of maritime, defence and security operations.
The vessels were spotted transiting through the Irish Exclusive Economic Zone (EEZ) off the southwest coast on their way to take part in naval exercises in the Atlantic.
The Russian naval exercises were initially due to take place within the EEZ but over the weekend Russia announced that, "as a gesture of good will, they would be relocated.
At least five Russian ships have been spotted by the Defence Forces since February 1st. Russian ambassador Yuriy Filatov told an Oireachtas committee this week that the drills would involve only two ships.
“As far as the embassy knows, the exercises in question involves two ships,” a Russian embassy spokesman repeated on Thursday.
The Russian flotilla comprised the Marshal Ustinov, an advanced missile cruiser and one of the largest vessels in the Northern Fleet, along with the Admiral Kasatonov, the Stoikiy and the Soobrazitelnyy, a "guided missile cruiser" which was seen with a helicopter on its deck.
They were accompanied by a support vessel called the Ekhorov. A submarine is also likely to be accompanying the ships, per Russian naval doctrine, but this could not be confirmed.
On Wednesday night an Air Corps' Casa maritime patrol aircraft observed two of Russian warships within the EEZ about 140 nautical miles (260km) southwest of Kerry Head.
A Defence Forces spokeswoman said all vessels were outside Irish territorial waters, which extend 12 miles from the coast, and are therefore acting in accordance with international law. “There is no restriction on warships operating on the high seas inside and outside of exclusive economic zones.”
During the day the Air Corps also observed two French naval ships, accompanied by RAF Typhoon fighter jets, outside the EEZ which were shadowing the Russian vessels. The Naval Service's LE Samuel Beckett was also in the area monitoring the ships' movements.
The US Navy’s USS Roosevelt, a destroyer equipped with two helicopters, was also observed by the Defence Forces.
The RAF was conducting a large number of flights in response to the ships, and to the unannounced arrival of Russian military aircraft around its EEZ.
Military experts believe the Russian drills will now take place in an area in the Atlantic just outside the Irish EEZ but still in the vicinity of vital subsea communications cables which link Europe to north America.
The drills, which are part of a series of Russian naval exercises taking place around the globe, coincide with the build-up of Russian troops on the border with Ukraine.
Mr Filatov has said the exercises have nothing to do with the troop build-up and that there are no plans to invade Ukraine.