MOSCOW, August 4. /TASS/. A criminal case has been opened against a detained participant of Saturday’s unauthorized rally in Moscow, who has been charged with using violence against a riot police officer, a source in the law enforcement agencies told TASS.

"An investigator of the Investigative Committee has opened a case against citizen Ustinov under Part 1 of Article 318 of the Russian Criminal Code," the source said.

This was the first criminal case launched after the August 3 unauthorized opposition rally. According to the source, the man put up active resistance to the National Guard’s riot police officer during his detention.

The officer was hospitalized with a left shoulder slip and will be later sent to the National Guard’s hospital.

According to the Interior Ministry’s department in Moscow, some 600 people were detained for taking part in the unauthorized rally in Moscow on Saturday, which drew nearly 1,500 people.

The Moscow authorities had warned the rally’s participants about their responsibility and that they must not violate the law. The police had warned about the risks of various provocations at the unauthorized rally on August 3 and called on citizens and guests of the capital to avoid participation in it.

Moscow’s prosecutors have launched an investigation into administrative offence against 15 unregistered candidates to the Moscow City Duma (parliament), who organized the unauthorized rallies on July 14 and July 27. They had ignored the warnings.

According to the Investigative Committee, more than 10 citizens had an active part in staging mass riots in Moscow, and six of them have been arrested under the court’s ruling.