An activist from the Solidarnost democratic opposition movement has died two months after being attacked with an iron rod.

Alexei Stroganov fell into a coma after the assault and never regained consciousness, Moscow deputy and Solidarnost member Ilya Yashin wrote Wednesday on Facebook.

“[Stroganov] passed away yesterday,” Yashin wrote.

Yashin did not give any further details on the attacker’s motivation or identity but said municipal deputies would ask authorities to open an investigation into Stroganov’s death.

Responding to a social media comment asking why news of the attack received next to no coverage, Yashin stressed that “we didn’t know anything.”

“He went missing two months ago and didn’t make contact. We only found out about what happened yesterday,” he wrote.