June 4 marks the birthday of the late opposition politician Alexey Navalny, who died in a Russian prison. He would have turned 49. Around 20 people gathered at Moscow’s Borisovskoye Cemetery, where Navalny is buried, to mark the occasion, according to the outlet Sotavision. Among them were his mother, Lyudmila Navalnaya; his widow’s mother, Alla Abrosimova; and the parents of opposition politician Ilya Yashin.

Lyudmila Navalnaya thanked those who came “for remembering my son, for coming here,” The Insider reports. A memorial prayer was read at the gravesite by Father Dmitry Safronov, a priest who was barred from ministry after leading a memorial service at Navalny’s grave 40 days after his death. According to Sotavision, Russian National Guard officers checked bags — and even flower bouquets — at the cemetery entrance, while about 10 officers from Russia’s Center for Combating Extremism (Center “E”) filmed the mourners on their phones.