A Council of Europe official sent a letter to the Russian government Thursday requesting information on allegations of improper policing during recent Alexei Navalny protests.

Dunja Mijatovic, the Commissioner for Human Rights at the Council of Europe, wrote in the letter that her office has received “numerous reports of excessive use of force and violence against peaceful protests” and is seeking clarification on the Ministry of the Interior’s methods on policing during recent protests.

Protesters have organized demonstrations across Russia in recent weeks in response to the arrest and sentencing of opposition leader Navalny. On February 2, a court found the opposition leader to have violated his probation, but Navalny maintains that he is innocent and further accuses the Russian government of attempting to assassinate him using a chemical nerve agent.

Mijatovic’s letter also documents reports of inhumane detention of arrested protesters. Specifically, it emphasizes that detainees have allegedly not received medical or legal assistance, and in some instances, “demonstrators are [still] kept in police vans in appalling conditions due to the inability of the relevant authorities to provide them with due facilities.”

More than 11,000 people have been detained at recent protests. On January 31 alone, authorities arrested 5,754 individuals at demonstrations.

Though not clear if in response to Mijatovic’s letter, the Ministry of Internal Affairs released a statement Thursday citing a “difficult epidemiological situation” for restrictions on gatherings. The government urged citizens to refrain from being involved in unauthorized events.

Navalny has appealed his conviction and a hearing is set for February 20.