The protests in Russia on Sunday — nominally against corruption but also a rare show of public defiance against Mr. Putin, who has found a fierce and enduring critic in Mr. Navalny — were the largest coordinated display of public dissatisfaction since anti-Kremlin demonstrations in 2011 and 2012, after an election that was tainted by fraud.

Protesters tried to prevent a police van from taking Mr. Navalny away and chanted: “This is our city. This is our city.” Others shouted, “Russia without Putin,” and held up pieces of paper denouncing the Russian president and his allies as thieves.

In a Twitter post, Mr. Navalny urged his followers to continue with the demonstration after he was grabbed by police officers as he tried to join the crowds along Tverskaya Street in the center of Moscow.

“Guys, I’m O.K.,” he wrote in a message in Russian. “No need to fight to get me out. Walk along Tverskaya. Our topic of the day is the fight against corruption.”

The Moscow Police Department said on its website that “around 500” people had been arrested in the city for taking part in an “unapproved public event.” OVD-info, a group that monitors arrests, said the number of arrests in Moscow was at least 1,000.

Instead of waving big banners with antigovernment slogans as in previous protests, most of those who joined Sunday’s walk on Tverskaya Street displayed their feelings discreetly. Some waved Russian flags, cloaking their opposition in the same patriotism that Mr. Putin has used so successfully to boost his popularity.