A number of government websites in Ukraine were down on Friday after a huge hacking attack, Ukrainian officials said.
While it was not immediately clear who was behind the attacks, they come amid heightened tensions with Russia and after talks between Moscow and the West failed to yield any significant progress this week.
“As a result of a massive hacking attack, the websites of the Ministry of Foreign Affairs and a number of other government agencies are temporarily down. Our specialists are already working on restoring the work of IT systems,” spokesman of Ukraine's Foreign Ministry Oleg Nikolenko wrote on Facebook on Friday.
Nikolenko told The Associated Press it was too soon to tell who could have been behind the attacks. "It's too early to draw conclusions as the investigation is ongoing, but there is a long record of Russian cyber assaults against Ukraine in the past,” he said.
Moscow had previously denied involvement in cyberattacks against Ukraine.
Websites of the country's Cabinet, seven ministries, the Treasury, the National Emergency Service and the state services website, where Ukrainians' electronic passports and vaccination certificates are stored, were unavailable Friday as the result of the hack.
The websites contained a message in Ukrainian, Russian, and Polish, saying that Ukrainians' personal data has been leaked to the public domain. “Be afraid and expect the worst. This is for your past, present and future," the message read, in part.
Ukraine's State Service of Communication and Information Protection has said that no personal data has been leaked.
The US estimates Russia has massed about 100,000 troops near Ukraine, a buildup that has stoked fears of an invasion. Moscow says it has no plans to attack and rejects Washington's demand to pull back its forces, saying it has the right to deploy them wherever necessary.
The Kremlin has demanded security guarantees from the West precluding NATO's expansion eastwards.
Last month, Moscow submitted draft security documents demanding that NATO deny membership to Ukraine and other former Soviet countries and roll back the alliance's military deployments in Central and Eastern Europe. Washington and its allies have refused to provide such pledges, but said they are ready for the talks.
High-stakes talks this week between Moscow and the US, followed by a meeting of Russia and NATO representatives and a meeting at the Organization for Security and Cooperation in Europe, failed to bring about any immediate progress.