Unlike the nationwide demonstrations organized on March 26 by the anti-corruption activist Aleksei A. Navalny, the protest on Saturday was approved by the authorities beforehand, and, while out in force, police officers and members of the Russian National Guard, an internal security force set up last year, did not try to disrupt the gathering. The crowd was also much older than the ones at Mr. Navalny’s rallies, which drew mostly youthful protesters in March.

Mr. Navalny, 40 and Russia’s most charismatic opposition figure, was absent from Saturday’s rally, which was organized by an older generation of Kremlin critics like Lev Ponomarev, a Soviet-era human rights activist.

Demoralized and mostly silenced for years by official harassment and a barrage of propaganda on state-controlled media that portrayed them as traitors, opponents of Mr. Putin have again found their voice in recent months with an unusual series of modest but, for the Kremlin, unnerving street protests. The March 26 anticorruption rallies, held in nearly 100 towns across the country, were followed last month by protests in about 30 cities initiated by Open Russia, an organization founded by the exiled billionaire Mikhail B. Khodorkovsky that was recently banned by Russia’s prosecutor general as “undesirable.”

The Saturday rally drew diverse and sometimes contradictory groups, including gay-rights activists, extreme nationalists, hard-line socialists, opponents of hunting and critics of a Moscow city government plan to resettle hundreds of thousands of residents so their buildings can be replaced by new developments. A similarly broad coalition of Kremlin opponents drove the 2011-2012 protests, which at their peak brought up to 100,000 people into the streets but fizzled after a wave of arrests and prison sentences.

“There are lots of very different people here, but this shows a lot of people are angry about something,” said Ildar Feseyev, a 65-year-old member of Yabloko, a liberal party, who joined the protest. Nearby, burly young men waved the old Russian imperial flag and shouted for the release of Dmitri Demushkin, a nationalist recently sentenced to two and half years in prison for inciting hatred.