Prime Minister Vladimir V. Putin, in an interview published on Monday, said violent crackdowns on public demonstrations in Moscow and other major cities were sometimes proper.

Opposition protests are routinely broken up in Russia by the police, who maintain that they have not been approved local authorities. Mr. Putin told the Kommersant newspaper that the opposition had to abide by the law and receive permission to march.

“If you get it? Go out and demonstrate,” he said. “If not, you have no right. If you go out without having the right — you are going to get beaten upside the head with a club. It’s as simple as that.”