At least two people have died and about 40 others were detained in what has been described as a crackdown on gay people in the Russian republic of Chechnya, LGBT activists said.
The new allegations come after reports in 2017 of more than 100 gay men being arrested and subjected to torture - with some of them killed - in the predominantly Muslim region.
Chechen authorities denied those accusations, and federal authorities conducted a probe that found nothing to support the reports.
The Russian LGBT Network, which has been monitoring the situation in Chechnya and helping victims of the anti-gay purge, said that about 40 men and women have been detained on suspicion of being gay since December and that at least two of them have died as a result of torture in detention.
The detainees are believed to be kept at the same facility which was named in the 2017 reports.
Igor Kochetkov, programme director at the Russian LGBT Network, said: "Widespread detentions, torture and killings of gay people have resumed in Chechnya.
"Persecution of men and women suspected of being gay never stopped. It's only that its scale has been changing."
Mr Kochetkov said the new wave of persecution started at the end of the year when Chechen authorities detained the administrator of a social media group popular with LGBT people in the North Caucasus.
He said the mass detentions began after the authorities got hold of contacts on the man's mobile phone.
Colm O’Gorman, Executive Director of Amnesty International Ireland said the news that a crackdown on LGBT people has resumed is "absolutely spine-chilling".
“Many LGBTI people in Russia are still traumatised by the 2017 purge which saw dozens of gay men in Chechnya abducted and tortured and others killed."
He added: “We are horrified by reports that at least two people have died from torture-inflicted injuries. With lives in jeopardy, there is an urgent need for an international response to protect gay and lesbian people in Chechnya.”
Russian authorities have strenuously denied that killings and torture took place in the predominantly Muslim region where homosexuality is taboo, even after one man came forward to talk about the time he spent in detention in Chechnya.
Maxim Lapunov said he was detained by unidentified people on a street in the Chechen capital, Grozny, in 2017 and kept in custody for two weeks, where he was repeatedly beaten.
He was let go after he signed a statement acknowledging he was gay and was told he would be killed if he talked about his time in detention.
Mr Lapunov, who is not an ethnic Chechen and is from Siberia, was the first to file a complaint with Russian authorities over the wave of arrests of gay people.
The Organisation for Security and Cooperation in Europe last month called on Russia to investigate the reports, and Mr Lapunov's case specifically.
Mr O'Gorman added: “The fact that there has still not been any justice for the 2017 attacks shows that gay and lesbian people in Chechnya cannot rely on the Russian authorities to protect them. The lack of official investigation has emboldened the Chechen authorities to launch a new wave of persecution, safe in the knowledge that the Russian government will back up their denials and obfuscation.
“We are calling for the international community to take immediate action to protect gay and lesbian people in Chechnya, and to increase the pressure on the Russian authorities to properly investigate these horrendous crimes.”