MOSCOW (AP) — A human rights activist says Moscow police have arrested at least five protesters at an unsanctioned rally outside the headquarters of the Federal Security Service (FSB), the successor agency to the KGB.

Oleg Yelanchik told the Interfax news agency that five people were arrested outside the building, while another three were arrested after they left the protest. There was no immediate comment from Moscow police.

The rally, which drew around 50 people, was held in place of a march proposed by 77-year-old human rights activist Lev Ponomaryov.

Ponomaryov was sentenced to 25 days in jail on Dec. 5 for a Facebook post in which he called for a protest in October outside the FSB headquarters to back several teenagers accused of extremism in a case widely described as trumped up.