Police broke up an unsanctioned gay rights rally in central Moscow on Saturday, detaining around 20 people, including anti-gay campaigners who attacked the activists.

The campaigners had requested permission to hold a gay pride parade today, but Moscow authorities blocked the request for the tenth year in a row — an annual ritual that has come to symbolize Russian authorities' hostility to public expressions of support for gay rights.

A 2013 law against gay "propaganda" also sparked an outcry among Russian rights activists and in the West. But partly reflecting the influence of the Orthodox church, many Russians back the law or have negative feelings towards gays.

Activists at Saturday's meeting on Tverskaya Square near the city centre were heavily outnumbered by black-clad riot police who had lined the square in advance.

"It is lawlessness of Moscow's and Russian authorities - what is happening here is a complete lawlessness," said Nikolai Alexeyev, a leading Russian gay rights activist, as he was dragged into a police van with a bleeding hand. "We are just trying to hold a peaceful human rights action."

Reuters witnesses saw some of the anti-gay activists attack peaceful gay activists before they were separated by police.

A group of homophobic protesters also showed up at the rally, violently attacking demonstrators. (Maxim Shemetov/Reuters) Two pro-gay activists on a quad bike, waving rainbow-coloured flags and letting off orange smoke, were charged by the anti-gay activists and dismounted on Tverskaya Street, the main road leading past Tverskaya Square.

Demonstrators were able to unfurl a rainbow flag for a short time - reading "Make love not war" - but they were also attacked by an anti-gay group before riot police ripped the flag away.

Elena Kakhtaryova, an anti-gay activist, was standing peacefully with a placard that read: "No to euro gay values. No to a euro gay way of development. Only Russia and only victory."

"I'm against this phenomenon which is imposed on us, against homosexuality, against non-traditional values to put it mildly, or speaking (plain) Russian: against pederasty and sodomy," she said.