Chastened by the protests in Istanbul, Muscovites rallied Wednesday in a show of support for the 12 opposition defendants on trial for their actions a year ago in a clash with Russian police.

Estimates of the crowd’s size varied but suggest that as many as 15,000 people may have taken part in the low-key march. The turnout was far less than the tens of thousands present at protests a year ago, but those who participated Wednesday said they wanted to remind the public, and one another, that the opposition hadn’t disappeared.

Walking a dachshund named Snark, Maria Sakson said the marchers showed up on the Russia Day holiday so that President Vladimir Putin would know the protest movement still exists.

“We haven’t come to terms,” she said.

She can only look wistfully at Istanbul, a city she has visited twice, and which has seen huge protests this month in Taksim Square. “There are so many more brave people there than here,” she said. “We’re spoiled in many ways. And as a nation, we are used to being patient.”

Among those of her friends who aren’t so patient, she said, many are making plans to leave Russia — something that Sakson, a 36-year-old architect, doesn’t want to do. The alternative is to protest, she said.

Nikolai Maroko, 34, who works for a translation service, said he came out Wednesday for one reason: “To feel that I am not alone.”

He echoed Sakson in comparing Russia to Turkey, where protests have occurred in dozens of cities. “Turkey makes us feel rather envious,” he said. “It is sad for me. We are in for a rather cold period. But there can be no end of this, only a pause.”

The rally was called the March Against Executioners, and it was designed to show solidarity with those who were arrested and charged with rioting after clashes with police at a rally May 6, 2012, on the eve of Putin’s inauguration. Some of the defendants have been in jail since and face steep sentences upon their inevitable convictions.

Russia’s top health official, Gennady Onishchenko, tried to warn people away from the march. In a city where summer temperatures in the 90s are considered uncomfortable but not that unusual, he cautioned, unconvincingly, that Wednesday’s expected high of 70 degrees could pose the danger of heatstroke. When the march ended, it was 64. There were no reports of anyone collapsing from the heat.

Police detained a dozen people for carrying the banner of the banned Left Front movement.

Putin, meanwhile, extolled democracy at the founding congress of the Popular Front, a political organization he is forming now that the ruling United Russia party has become a damaged brand, disparaged as the “party of crooks and thieves.”

“Russia needs everyone’s contribution,” Putin said, “sincere involvement in the general improvement of the country. Not tomorrow, but today.”