Moscow, May 5 (IANS/RIA Novosti): A Russian gay rights activist has become the first person to be fined under a new law banning homosexual propaganda in St. Petersburg.

Nikolai Alexeyev, the leader of GayRussia, was fined 5,000 rubles ($170) by a court Friday, after he was detained for picketing outside St. Petersburg's legislature building last month protesting what he described as the "homophobic" new law.

Alexeyev denies the accusations against him.

The legislation, which makes it illegal to "disseminate homosexual propaganda" among minors, was signed in March, making St. Petersburg the fourth Russian city to adopt the ban.

Several politicians and church figures have called for the law to be passed at a federal level. The law sets fines of up to 500,000 rubles ($17,000) for violations.

Last month, a number of gay campaigners were fined in Russia's southern Astrakhan region.

Homosexuality was decriminalised in Russia in 1993, but anti-gay sentiments remain strong in society. No gay parade has ever been officially sanctioned in Russia.

According to a 2010 survey by Russia's independent polling agency Levada Center, 74 percent of respondents said gays and lesbians were "amoral" and "mentally defective", while only 45 percent said they should enjoy the same rights as heterosexuals.

Pop singer Madonna has pledged to speak out against the law when she performs in St. Petersburg in August.

At least 17 gay rights activists were detained at a May Day demonstration in St. Petersburg, the city's LGBT (lesbian, gay, bisexual, transgender) group Coming Out said.