Prominent Russian opposition politician and former deputy Prime Minister Boris Nemtsov was shot dead in central Moscow Friday night, according to a government statement quoted by the Interfax news agency. An unidentified attacker shot Nemtsov, 55, four times while he was walking near the Kremlin.

Police are investigating the shooting, which reportedly took place after a car with a group of men approached Nemtsov, who was walking with a colleague at the time. An associate of Nemtsov’s confirmed his death, saying, "unfortunately, I'm currently looking at the body of Nemtsov on the Zamoskvoretskiy bridge,” RT reported. “I see the body, and a lot of police."

 

Nemtsov served as deputy prime minister under the government of former Russian President Boris Yeltsin. The politician, who was once considered a likely candidate for president, was known for being a vocal critic of current Russian President Vladimir Putin, according to Sputnik International.

He rose to prominence as governor of the city of Nizhny Novgorod before becoming deputy prime minister in the late 1990s, the New York Times reported. Nemtsov served in Russia’s parliament until 2003, after which he founded and led several opposition organizations, most recently including the Republican Party of Russia – People’s Freedom Party.

Nemtsov died just before a scheduled march in Moscow Sunday against the war in Ukraine, which he had been vocally promoting, the BBC said. In his last tweet, Nemtsov urged Russia’s fractured opposition to unite at the anti-war march. "If you support stopping Russia's war with Ukraine, if you support stopping Putin's aggression, come to the Spring March in Maryino on 1 March," he wrote. Putin has been widely accused of being behind the rebellion in eastern Ukraine, which has left more than 5,000 people dead in the past 10 months. The president has denied these charges, however.