Russian opposition leader Alexei Navalny at a mass march on the one-year anniversary of dissident Boris Nemtsov's killing on Feb. 27, 2016 in Moscow, Russia.

Russian opposition leader Alexei Navalny has been arrested in Moscow as protest demonstrations called by him took place across the country.

He has called on supporters to continue the demonstrations despite his arrest Sunday.

He says on Twitter "they have detained me. This doesn't mean anything ... you didn't come out for me, but for your future."

Protests ranging from a few dozen to several hundred people were reported throughout the country.

Navalny is calling for a boycott of the March 18 presidential election in which President Vladimir Putin is seeking a fourth term.