MOSCOW (Reuters) - Russia's lower house passed a law on Tuesday banning gay "propaganda", a measure that human rights groups say has already fuelled attacks on homosexuals as President Vladimir Putin pursues an increasingly conservative social agenda.
As parliament debated the bill, gay activists who had taken part in a "kissing protest" outside parliament to demonstrate against the law were harassed and pelted with eggs by anti-gay protesters, then about 20 of them were arrested.
The law bans the spreading of "propaganda for non-traditional sexual relations" to minors and sets heavy fines for violations. It passed with 436 votes in the 450-seat lower house, the Duma. One deputy abstained and no one voted against.
"Traditional sexual relations are relations between a man and a woman, which ... are a condition for the preservation and development of the multi-ethnic Russian people," lawmaker Yelena Mizulina told the chamber.
"It is precisely these relations that need special protection by the state," she said.
Critics say the bill - a nationwide version of laws already in place in several cities including Putin's hometown of St Petersburg - would in effect ban all gay rights rallies and could be used to prosecute anyone voicing support for homosexuals.
"There is already enough pressure and violence against gays, and with this law it will only continue and probably get worse," said Viktoria Malyasova, 18, standing outside the Duma.
"I may not be gay but I came to stand up for my rights and the rights of other people to love whom they want," she said.
There are no official figures on anti-gay crime in Russia, but in an online poll last year, 15 percent of about 900 gay, lesbian, bisexual or transgender respondents said they had been physically attacked at least once in the previous 10 months.
Putin, who has embraced the Russian Orthodox Church as a moral authority and harnessed its influence as a source of political support, has championed socially conservative values since starting a new, six-year term in May 2012.
The gay rights protesters outside the Duma on Tuesday were far outnumbered by around 200 anti-gay activists who surrounded them, chanting "Russia is not Sodom", singing Orthodox Christian prayers, crossing themselves and throwing rotten eggs.
After scuffles in which one man was knocked to the ground and kicked by the anti-gay activists, police began detaining the gay protesters and bundling them into waiting buses.
Moscow police said about 20 people were detained.
Investigators say homophobia was the motive for the brutal murders of two men in the past month, one in eastern Russia and one in the southern city of Volgograd.
The 60-year-old president denies that there is discrimination against gays, but has criticized them for failing to increase Russia's population, which has declined sharply since the collapse of the Soviet Union in 1991.
The Duma passed another law on Tuesday that made the insulting of religious feelings a crime punishable by up to three years in prison - a measure proposed after last year's Pussy Riot protest at a Moscow cathedral.
Two members of the feminist performance group are serving two-year jail sentences for "hooliganism motivated by religious hatred" after a trial that drew international criticism.
Both bills still need the approval of the upper house, and Putin's signature.
Additional reporting by Maria Tsvetkova; Editing by Kevin Liffey; Writing by Steve Gutterman and Thomas Grove; Editing by Kevin Liffey