Thousands rally in Moscow to commemorate slain opposition leader before election

People attend a rally, which marks the third anniversary of Russian opposition politician Boris Nemtsov's death, in Moscow, Russia February 25, 2018. REUTERS/Sergei Karpukhin

MOSCOW (Reuters) - Thousands marched through central Moscow on Sunday to commemorate murdered Russian opposition leader Boris Nemtsov, calling for President Vladimir Putin to be ousted just three weeks before a presidential election.

Nemtsov, one of Putin's most vocal critics, was shot dead on Feb. 27, 2015 as he walked across a bridge near the Kremlin. Aged 55, he had been working on a report examining Russia's role in the conflict in Ukraine.