A rights activist who was attacked while guarding a makeshift memorial to assassinated Russian politician Boris Nemtsov has died in the hospital, friends said.
Ivan Skripnichenko died early on August 23, a day after he was hospitalized for the second time since he was attacked on August 15 by an assailant who broke his nose, Andrei Margulev told RFE/RL on August 25.
"Tragedy at the Memorial," Margulev wrote earlier on Twitter. "Ivan died yesterday."
The attack came on the 900th day after Nemtsov, a former first deputy prime minister and a prominent opponent of President Vladimir Putin, was shot dead at close range on a bridge near the Kremlin on February 27, 2015.
Seeking to honor Nemtsov and keep his memory in the foreground at a time when government critics say the Kremlin is seeking to silence dissent, activists put together a makeshift shrine at the spot where he was killed.
Assailants have frequently vandalized the memorial.
In July, a Moscow court convicted five men from Russia's North Caucasus region of Chechnya of Nemtsov's murder, but relatives and associates believe the killing was ordered at a higher level. They say justice will not be done until the person or people behind the slaying are identified and prosecuted.
As with previous killings, including that of investigative journalist Anna Politkovskaya in 2006, government critics have voiced suspicion that the culprits will never face justice because the trail of an honest investigation could lead close to Moscow-backed Chechen leader Ramzan Kadyrov or Putin's government.
Media reports cited another activist, Tamara Lugovykh, as saying that a "very aggressive" man began shouting at Skripnichenko at the memorial on August 15 and then punched him and broke his nose.
Eyewitnesses said the attacker shouted, "What, you don't like Putin?!"
Skripnichenko, 36, went to the Sklifosovsky emergency hospital in Moscow after the attack and was released the following day, state-run news agency RIA Novosti reported.
Margulev, a fellow activist who has also spent time guarding the Nemtsov memorial, told RFE/RL that Skripnichenko was hospitalized again early on August 22, at a different hospital, and died in an emergency care ward at about 3 a.m. on August 23.
Media reports quoted Margulev as saying that there were no autopsy results yet but that he suspects Skripnichenko may have died as the result of a blood clot.
With reporting by Carl Schreck, RFE/RL's Russian Service, Mediazona, Interfax, and BBC