Russian police have arrested several gay rights activists and Russian nationalists who confronted them at a rally declared illegal under a new law against "gay propaganda".
Officials in St Petersburg deemed that Saturday's rally, which took place in a space designated for public demonstrations, violated the law.
The statute prohibits public displays of homosexuality.
About 200 nationalists also gathered at the rally, chanted slogans such as "Sodomy will not pass," and threw eggs and rocks at the gay-rights activists, who numbered about 40.
The state-run Itar-TASS news agency quoted an unnamed police official as saying police arrested dozens of people, including eight nationalists.
Russia's parliament passed a law banning "gay propaganda" earlier this month. St Petersburg was one of several cities to pass similar laws at local level before that.