St. Petersburg’s city legislature approved on Wednesday a bill imposing fines up to $16,700 for the promotion of homosexuality.
It follows similar bans in the southern Astrakhan and central Ryazan and Kostroma regions in Russia.
St. Petersburg lawmakers postponed a debate on the bill in November last year after a disagreement over “legal definitions” and the amount of the fines.
Several gay rights activists were detained as they attempted to stage a protest outside the parliament building, the news website lenta.ru said.
The legislation effectively outlaws any gay pride events.
It also allows authorities to impose fines of up to 500,000 rubles ($16,700) for “public activities promoting homosexuality (sodomy and lesbianism), bisexualism and transgender identity” as well as pedophilia among minors.
The fines are 10 times higher than when the bill was first brought before the city’s legislature in November.
The authorities insist the ban is necessary to safeguard “minor’s moral and spiritual development,” but rights groups earlier warned of the slide towards legitimizing fascism.
The St. Petersburg LGBT group Coming Out said the bill was “homophobic” and aimed at diverting public attention from Russia’s “real political and social problems.”
Homosexuality was illegal in the Soviet Union and was only decriminalized by President Boris Yeltsin in 1993, but anti-gay sentiment is still widespread.