ST. PETERSBURG, March 6. /TASS/. Three participants in an unauthorized rally in St. Petersburg attacked police officers, two of them were detained, a spokesman for the Russian interior ministry’s St. Petersburg and Leningrad region department said on Sunday.

"On March 6, an attack was staged on police officers who tried to stop an unauthorized rally by its participants. Two of the attackers were detained, the third one fled but was identified. A criminal case was opened on charges of an attack on policemen (article 318 of the Russian Criminal Code)," he said.

Russian Interior Ministry Spokeswoman Irina Volk told TASS earlier on Sunday that some 750 people were detained during the unauthorized rally in St. Petersburg. According to Volk, such actions were held in Moscow and other Russian cities. Around 5,200 people took part and more than 3,500 of them were detained, she said.

Calls for rallies against Russia’s special military operation in Ukraine in Russian cities on March 6 were disseminated in the internet earlier. Russia’s interior ministry warned that attempt at organizing unauthorized rallies would be thwarted and their organizes and participants would be brought to responsibility.

Russian President Vladimir Putin said in a televised address on February 24 that in response to a request by the heads of the Donbass republics he had made a decision to carry out a special military operation in order to protect people "who have been suffering from abuse and genocide by the Kiev regime for eight years".