Russian police wrestled opposition leader Alexei Navalny into a patrol wagon on Sunday moments after he appeared at a rally to urge voters to boycott what he said would be a rigged presidential election in March.

Navalny has little chance of influencing the election, likely to be won comfortably by President Vladimir Putin, but his ability to use social media to mobilize crowds of mostly young protesters in major cities has irked the Kremlin.

The numbers attending Sunday's protests across Russia — some shouting "Putin is a thief" — appeared lower than previous demonstrations staged by Navalny, Reuters reporters said, suggesting momentum may have shifted away from him.