Several Polish news websites were hit by distributed denial-of-service (DDoS) attacks that the government said could be the action of Russian hacking groups, the digitalisation minister was quoted as saying on Thursday.
Warsaw has positioned itself as one of Ukraine's staunchest allies since Russia invaded the country, and Poland says it frequently faces Russian attempts to destabilise the situation in the country.
Moscow has consistently denied that it carries out hacking operations.
DDoS attacks work by directing high volumes of internet traffic towards targeted servers in a relatively unsophisticated bid to knock them offline.
"Having information that such attacks are being prepared, we immediately informed all interested editorial offices so that they had the opportunity to react to this situation," Janusz Cieszynski was quoted as saying by state-run news agency PAP.
Asked whether Russian groups were behind the attacks, Cieszynski said "we have such information".
The Russian foreign ministry did not immediately respond to an emailed request for comment.
According to PAP, the websites affected included those of daily newspapers Gazeta Wyborcza, Rzeczpospolita and Super Express.
Wyborcza confirmed on Twitter that it had been the victim of an attack, as did news website wPolityce.pl.
(Reporting by Alan Charlish and Karol Badohal; Editing by Alex Richardson)