Moscow: The Moscow mayor's office has refused to authorise a gay pride parade planned for May 25, and will thwart any unsanctioned action, an official said.
Gay activists filed a request earlier this week to stage a parade in the Russian capital, but the Moscow authorities said their application was unlikely to be approved.
They also declined to allow a picket in Moscow's Sokolniki Park.
"We have sent a notification to the organisers that we have not given a go-ahead to the event," the city's top security official Alexei Mayorov said.
Mayorov cited the society's likely "negative attitude" towards the action as a reason for banning the parade.
He also warned gay activists against trying to march without permission.
"If the organisers still try to hold the event, a certain reaction will follow and the action will be thwarted," Mayorov said.
In 2012, the city's highest court upheld a municipal government ban on gay pride parades for the next 100 years - passed after Nikolai Alekseyev, a leading gay rights activist, submitted a similar number of requests, filed in advance, the year before.
Homosexuality was only decriminalised in Russia in 1993, and anti-gay sentiment remains strong in society, including among Russia's political establishment.
In 2007, former Moscow mayor Yury Luzhkov described attempts to hold a gay parade in the capital as "satanic".
The Russian authorities have never sanctioned a gay pride rally, though LGBT activists have been applying for permits in Moscow since 2006.
Last May, the St. Petersburg authorities permitted a rally against homophobia, but its participants were attacked by dozens of masked thugs, all of whom evaded arrest.
A ban on spreading "gay propaganda" among minors, currently under review in the Russian legislature, envisages fines of 4,000 to 500,000 rubles ($130 to $16,500) for individuals and organisations trying to convince minors of the benefits of same-sex relations.
Local legislatures in several Russian regions, including St. Petersburg and Novosibirsk, have already passed a similar law.