Television station TV3 said it was hacked late Thursday and shortly after that a bogus story appeared on the channel's website accusing Defense Minister Raimundas Karoblis of sexually harassing a male radio journalist.
Tensions have been running high between Russia and Lithuania, which like other Baltic nations was long subject to Moscow's rule. Cyberattacks and disinformation campaigns have become more frequent in the last few years.
Defense Vice Minister Edvinas Kerza told reporters the national cybersecurity center is investigating the case and the internet protocol address (IP) of the hacker had been traced to St. Petersburg in Russia.
Attributing hacks is often difficult and the AP could not immediately corroborate the claim.
Russian officials didn't immediately comment on the reports of possible hacking in Lithuania but the government routinely denies ordering hackers to strike at Kremlin opponents.
The editor of the website also blamed Russian hackers.
"It is not the first Russian hacker attack on our website. They began when Russian government institutions demanded we delete two articles about Vladimir Putin. I refused and soon after we received an email from Russian institutions, informing us our site was blocked in that country. Cyberattacks followed shortly after that," editor Arturas Anuzis told The Associated Press.
Most of the letters were sent from the Russian Ministry of Communications and Mass Media, Anuzis said.
In a separate disinformation campaign this week, the Lithuanian Foreign Ministry was forced to deny false but widely published reports that Lithuania had imposed economic sanctions on Mongolia.
"We face a pretty huge and long-lasting disinformation campaign against our society. The power of propaganda is much harder to quantify than tanks or planes, but it was clearly aimed at a very huge variety of targets," said Tomas Ceponis, an analyst for the Lithuanian military.
TV3 and its website have been repeatedly targeted by hackers who have compromised the group's networks half dozen times. Government, parliament and other institutions' websites in Lithuania have seen several major cyberattacks every year.
Defense Minister Karoblis Facebook account was hacked and erased last year, but investigators were not able to prove a direct link to Russian hackers.
Lithuania regularly imposes three-month bans on Russia's TV channels for "incitement to war, discord and hatred."
Lithuanian citizens are actively fighting back, working to shut down people disseminating bogus news stories by reporting them to social media sites such as Facebook. Thousands of these activists saw their personal details exposed on a Russian website recently and some were openly threatened, according to Ricardas Savykynas, who leads a civic group.
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