Lawmakers from the ruling United Russia party have backed a controversial bill imposing fines for the promotion of gay "propaganda" among young people in the city of Saint Petersburg. The bill proposed by the United Russia faction was passed in its first reading on Wednesday in the city's parliament, where the party controls 23 out of 50 seats. It would need to be passed in two further readings to become law. Gay rights activists held pickets and gathered signatures in a petition against the bill. Two people were detained Wednesday for standing with protest signs near the parliament building, local media reported. Under the bill, anyone who committed "public acts" promoting homosexuality, bisexuality or transgender identity to minors could pay up to 3,000 rubles ($97.50), while an organisation could pay 10,000 to 50,000 rubles. The bill gave no definition of a public act, with activists saying it could be used to crack down on gay pride events, which are regularly banned in Russia. The bill also imposes the same fines for promoting paedophilia, tacitly equating it with homosexuality, which was decriminalised in Russia in 1993 under the presidency of Boris Yeltsin. Its backer Vitaly Milonov of the United Russia party said it was intended to "stop the flow of immoral information that pours over children and young people," in an official commentary. "Sometimes parents and schools are unable to stand up to the powerful showbusiness industry that promotes immorality and permissiveness," he said. The Memorial Anti-Discrimination Centre in St Petersburg, a rights group, issued a statement calling for deputies to vote down the bill, saying it "contradicted Russian and international legal norms." If passed, the bill "will spoil the reputation not only of Russia but of Saint Petersburg as a European city," Igor Kochetkov of the city's LGBT Network rights group said in a video blog. The bill had the aim "on the eve of elections to get the votes of the most conservative voters," he said. Casual homophobia is common in Russia, where almost no public figure has spoken openly about being gay.