The Government is in contact with the Irish embassy in Moscow as rebel mercenaries are advancing on the Russian capital.
The Wagner Group, which has played a major role in Russia's war in Ukraine, sent fighters across the Ukrainian border into Russia, seizing the city of Rostov overnight.
Russian president Vladimir Putin has vowed to punish those responsible for the armed mutiny, after Wagner chief Yevgeny Prigozhin said the "evil" of Russia's military leadership "must be stopped".
A spokesperson from the Department of Foreign Affairs said on Saturday afternoon that the Government "remains in close touch with our embassy in Moscow".
While the department has advised against all travel to Russia for some time now, it has updated its travel advice page for the Russian Federation due to the unfolding situation there.
"In light of the current situation, Irish citizens still in Russia should avoid all travel to the regions surrounding Rostov-On-Don and the regions bordering Ukraine, and if you are in those regions you should shelter-in-place, follow the instructions of the local authorities, and use your local networks for the most up-to-date information.
"Counter-Terrorism protocols are in place in several regions, including Moscow, giving the local authorities greater powers to block transport routes, ask for ID documents, and conduct searches. Please therefore be cautious when planning travel, keep your passport and visa documents, or copies of these, on your person at all times, and avoid public gatherings," the department's advice states.
The department spokesperson added the Irish embassy in Moscow is in ongoing contact with Irish citizens who remain in Russia who are registered with the embassy, adding that those who are not registered can do so on the department's website.
Meanwhile, the British government has called a meeting of its emergency committee to discuss the latest developments, while Britain's foreign secretary James Cleverly took part in a meeting with his counterparts from the Group of Seven (G7) major advanced economies.
The UK has also updated its travel advice to warn there is "a risk of further unrest across the country".
Britain's defence ministry added the move by Wagner Group mercenaries "represents the most significant challenge to the Russian state in recent times".
