Russia has blocked the website of OVD-Info, a prominent human rights monitor tracking political persecution, the group said Saturday, as authorities press ahead with a crackdown on dissent.

Russia’s Supreme Court is considering whether to shut top rights group Memorial, which works with the monitor.

OVD-Info, which tracks opposition protests and also provides legal support to victims of political persecution, said the Roskomnadzor media regulator had blocked its website earlier this week.

“At the moment, we have not received a notice and do not know the reason for being blocked,” the group tweeted.

A Roskomnadzor registry of blocked websites showed that a Moscow region court had issued a ruling dated December 20 to “limit” access to the site.

The website was not accessible by AFP journalists in Russia on Saturday.

This year has seen a historic crackdown on Russia’s opposition and independent media, starting with authorities jailing top Kremlin critic Alexei Navalny.

In September, the justice ministry added OVD-Info to its growing list of “foreign agents,” a term with Soviet-era undertones, with the group calling the move an “act of political pressure”.

Memorial has said it fears it could be shut down by the end of the year.

Prosecutors accuse the rights group of breaching “foreign agent” legislation and justifying terrorism by releasing lists of political prisoners that include banned figures like Navalny.