Two opponents of a massive demolition plan by Moscow city authorities were the subject of separate attacks in the Russian capital.
An activist from Russia's opposition Yabloko party, Natalya Fyodorova, has temporarily lost her sight after an assailant splashed an unknown liquid on her face.
The leader of Yabloko party's Moscow branch, Sergei Mitrokhin, wrote on Twitter that the attack by the unknown assailant took place in Moscow on April 28.
According to Mitrokhin, Fyodorova was being treated in a hospital where doctors said they were confident she would regain her vision.
Yabloko wrote on its website that the attack may be linked to Fyodorova's opposition to the plan by Moscow city authorities to demolish 8,000 five-story Soviet-era apartment buildings in the Russian capital.
The plan has sparked protests among many Moscow residents.
President Vladimir Putin in February publicly backed the plan to demolish the buildings, which house about 1.6 million people. But Putin said on April 26 that he would not sign the law if it violated citizens' rights.
Russian State Duma Deputy Sergei Shargunov, a member of the Communist Party, said on April 28 that his apartment had been targeted in an arson attack on April 21, a day after he voted against legislation on the demolition of the apartment buildings.
Shargunov wrote on Facebook on April 28 that he believes arsonists sparked the fire on April 21 by throwing an incendiary object onto his balcony.
He said that one room was totally destroyed and that his father, who was in the apartment at the time, escaped unharmed.
Shargunov was one of four Communist lawmakers who voted against the bill on April 20, in the first of three required readings in the lower house.