Russian police officers arrest an activist during an unauthorized opposition protest marking one year since the start of protests against Vladimir Putin, in Moscow, on Dec. 15, 2012. (NATALIA KOLESNIKOVA/AFP/GETTY IMAGES)

Thousands of opponents of Russian President Vladimir Putin on Saturday crowded into a Moscow square infamous as the location of the state security forces, vowing not to let up pressure on their government after a year of protests that started with grand hopes for change in their country and ended far more tentatively.

They braved near-zero temperatures and official warnings against the gathering to hold an illegal protest in front of the imposing security headquarters. Many of the roughly 3,000 protesters laid flowers near a stone that commemorates victims of Soviet gulags in honor of what they say are modern-day political prisoners.

But Saturday’s protest was far smaller than earlier marches that had tens of thousands turning out onto the streets of Moscow, and its top leaders were arrested long before they had any chance to energize the crowd.

The opposition movement has faced deep difficulties in sustaining its energy since Putin prevailed in March elections and took quick action to crack down on dissent in the country.

For protesters such as Ekaterina Korobtsova, the past year has been radicalizing but also edged with disappointment. Saturday was no exception.

“I expected there’d be more people,” she said as she walked into the square Saturday afternoon, bundled under heavy layers to defend against biting winds, past rows and rows of heavily armored police officers whom she derided as “cosmonauts” for their spacemanlike helmets.

Before what many charged were fraudulent parliamentary elections in December of last year, Korobtsova, 45, didn’t go to protests, she said. But like many others of her prosperous generation, she grew fed up with the corruption that touches so many aspects of life in her country of 143 million.

So Korobtsova, a freelance translator and former investment adviser, started heading out into the streets to fight Putin’s 12-year rule, along with tens of thousands of her peers. The first time, at Bolotnaya Square, where high turnout shocked organizers and the government alike, was unsettling, she said, because she didn’t know what to expect. But soon protest became normal, even fun. The mother of a 9-year-old boy, she was able to recite the proper procedure for helping a person escape from riot police as though she had known it since childhood.

Even “if they start using tanks, I think people will still come,” she said the day before Saturday’s protest at a fashionable coffee shop owned by a socialite who is one of the opposition movement’s unlikely leaders. “They can’t scare us,” Korobtsova said.

‘What has changed?’

In the first heady months after December, the sense of mass mobilization gave the opposition movement an unusual potency as the white ribbons that are their symbol were displayed on lapels in Moscow and St. Petersburg.

But they were never able to offer a convincing alternative to Putin, and no one disputes that he was the clear winner of a March election that officially gave him 64 percent of the vote. Now, with Putin settling in to another six-year term, harsh new laws passed against protest and criminal charges filed against many opposition leaders, the future appears far less hopeful.

“A whole year of our lives has gone by, and what has changed?” Korobstova said. These days she dutifully turns out to protests to remind Putin that not everyone accepts him — even as she fantasizes about moving the United States, where she studied for two years in the 1990s.

“Most people with money are trying to escape,” she said.

On Saturday, protesters came in defiance of Moscow authorities who denied permission to gather at Lubyanka Square in front of headquarters of what was once the KGB, of which Putin was once an officer. They came despite risks that have increased significantly since they began the wave of protests a year ago.

Shortly after Putin was inaugurated in a pomp-filled ceremony in May, he instituted laws that pushed fines for illegal protest to about $9,000 for individuals, up from $60, and as much as $48,000 for organizers, up from $1,160. The average yearly salary in Russia is about $20,700.

Co-opting the issues

“What authorities are doing with the protest movement, they are making it more radical,” said Lilia Shevtsova, a political analyst at the Carnegie Moscow Center. “With the first wave subsiding, we have a paradox. The open movement is dwindling, but a general mood of fury within the protests is growing.”

Authorities have pursued criminal charges against top opposition leaders, the newest of which were filed on Friday against Alexei Navalny, a lawyer and blogger who has been able to bridge divides between right-wing nationalists and die-hard leftists. Navalny was accused of embezzlement along with his brother.

On Saturday, he spoke very briefly to protesters before he was bundled into a police van and detained until after the demonstration was dispersed. Three other organizers — Ksenia Sobchak, Ilya Yashin and Sergei Udaltsov — were also detained, with police saying they had called on people to participate in an unsanctioned event.

Putin has derided the protesters, but he has also made moves to co-opt their main issues, including firing his defense minister over accusations of corruption and telling top officials last week that he will take steps to limit their ability to keep money in foreign countries, a favorite way to hide illegally earned money and dodging taxes.

Saturday’s protesters were a mixture of old and young, prosperous and less so. And many acknowledged that they had little sense of how to proceed. Last month, Navalny started an online service to complain about unfixed problems in Russia’s vast stock of government-owned apartment buildings, an issue that has political overtones. Many at the square said they welcomed that new initiative, but that they also hungered for bigger change more quickly.

“In normal life, when you’re mad, you have it out and then you’re quiet. It’s harder to keep it going,” said Dmitri Titov, 50, an information technology specialist whose face was ringed with a fur-lined hood. “If we fail, we’ll have to start again from scratch,” he said.

A committed core of demonstrators, marked by the past year, say they will show up to fight no matter what. But few know where the next year will lead.

The government is “squeezing us into a smaller and smaller space,” said Korobtsova, the translator. “Maybe something will happen here, a change for the positive.”