Russian police arrested about 20 gay rights protesters demonstrating on Monday in St. Petersburg against the treatment of homosexuals in the southern Chechnya republic, one of the detained activists told Reuters.

A Reuters cameraman saw police bundling several gay rights activists into police cars at one location. The human rights group OVD-Info human, which monitors police arrests, said about 17 had been detained.

Western governments and human rights activists have long criticized the Russian authorities for their treatment of gay people.

Last month, Russian independent newspaper Novaya Gazeta reported that up to 100 gay men were being held and tortured in “camps” in Chechnya. It said at least three of them had been killed.

Chechnya’s Moscow-backed president Ramzan Kadyrov denies that human rights are routinely abused in his republic and his spokesman has called Novaya’s report “an absolute lie,” saying there were no gay men in Chechnya to be persecuted.

Igor Kochetkov, a well-known activist in Russia’s gay, lesbian and transgender community, told Reuters that he was among a group of 10 being detained in one St Petersburg police station. He said another group of about 10 had been transferred to a second location.

St. Petersburg police were not immediately available for comment.

“I was waving a rainbow flag (representing gay rights), and was shouting ‘Kadyrov should go to the Hague,’” Kochetkov told Reuters by telephone whilst in detention.

The gay rights activists had joined an opposition-led May Day rally in St. Petersburg, the second biggest city in Russia.

Russian news agency Tass last month cited investigators as saying they not received any complaints about the persecution of sexual minorities in Chechnya.

A second activist taking part in Monday’s march said it was too dangerous for gays in Chechnya, and their families, to speak out about their abuse.

“It is hard for them to say ‘Hello I am Chechen and I am persecuted in Chechnya’ because they have relatives there. Unfortunately there is pressure not only on gay people but also on their families. And it is very dangerous,” an activist, Alexei Nazarov, told Reuters TV.

(Reporting by Vladimir Soldatkin and Maria Vasilyeva; editing by Richard Lough)