The editorial offices of Perm region weekly newspaper Vecherny Krasnokamsk were badly damaged over the weekend in an arson attack, police said.

Closed circuit cameras show an unidentified assailant breaking a window of the paper's offices at around 4 a.m. Saturday and throwing a firebomb into the newsroom, destroying equipment and files, Interfax reported. No one was injured in the attack.

Editor Olga Kolokolova estimated the damage at 300,000 rubles ($10,000), the police said in a statement on their website. Krasnokamsk police said they had opened a criminal case in connection with intended destruction of property.

Kolokolova links the attack to a series of investigative articles published by the newspaper on corruption by the Krasnokamsk mayor's office, including embezzlement of budget funds, Interfax reported.

The mayor responded that he did not object to the newspaper continuing to be published.

The newspaper is published by the local branch of the liberal Yabloko party, and Kolokolova is the head of the party's branch, freedom-of-press organization Reporters Without Borders said in a statement Tuesday condemning the attack.

The media watchdog linked the incident in part to the upcoming presidential election.

"The intimidatory shadow cast by this act is all the greater because of the current pre-electoral climate and all the political parties taking part must unequivocally condemn it," the statement said.