The law will impose steep fines on any individual, media, or legal entity discussing "non-traditional sexual relations."
Reports indicate that about 60 participants were hauled away by police.
The Russian president says gays and lesbians are "not discriminated against in any way" in his country, despite a law that passed the lower house of Parliament unanimously banning discussion of or "promoting homosexuality to minors."
Russia's lower house approves another antigay piece of legislation.
Five people have been charged with crimes in association with the violent death of French student and activist Clement Meric
The speaker of Parliament in Italy reached out to a teen who contemplated suicide in a newspaper article.
Protesters want to send a disapproving message to France's president, François Hollande, who made LGBT equality a priority of his administration.
Russian police and right-wing zealots clashed violently with LGBT-rights protestors outside the nation's capitol.