The official Vatican website was taken offline on Wednesday following an apparent hacking attack, the Holy See said.
"Technical investigations are ongoing due to abnormal attempts to access the site," Vatican spokesman Matteo Bruni said, without giving any further information.
The suspected hack came a day after Moscow criticised Pope Francis's latest condemnation of Russia's invasion of Ukraine.
In an interview with a Jesuit magazine, the pope had singled out troops from Chechnya and other ethnic minorities in Russia for their particular "cruelty" during the war.
(Reporting by Crispian Balmer; Editing by Gareth Jones)
