Despite massive government pressure, tens of thousands of Russians demonstrated against President Vladimir Putin in Moscow on Tuesday, shrugging off recent police raids on opposition leaders' homes and a new law stiffening fines for public order offenses.

Leftist politician Sergei Udaltsov told AFP that more than 100,000 people took part in the protest march. By contrast the police said the so-called March of the Millions numbered only 18,000. The Moscow city administration had authorized a demonstration for up to 50,000 people.

The Russian government said a total of 12,000 officers from the police and Interior Ministry were deployed in the city.

Defying a heavy downpour that some joked had been orchestrated by the president himself, protesters waved flags and shouted "Russia without Putin,""Putin to jail!" and "All power to the people!"

Helmeted riot police manned metal barriers along parts of the route. Ilya Ponomaryov, an opposition lawmaker, said about 60,000 to 70,000 people had turned out, much higher than the police estimate of 18,000.

'Beyond Being Scared'

The demonstrators included middle class people who prospered in Russia's oil export-driven economic boom and now want a greater political say. They also fear that the economy could stagnate in Putin's third term as president.

It was the first major rally since Putin was sworn in on May 7. "Those who fought are beyond being scared," Valery Zagovny, a 50-year-old who served for the Soviet army in Afghanistan, told Reuters.

After tolerating the biggest protests of his 12-year rule while seeking election, Putin has signaled a harsher approach to dissent since the start of his new term as president. Putin easily won a six-year term on March 4 after four years serving as prime minister.

His calls for stability are supported by elderly people and many outside the cities, as are his strong measures against the protesters. But opposition leaders say Putin's heavy-handed tactics show he is worried that the protests could pose a challenge to his once undisputed authority.

On Friday, he signed a law increasing fines, in some cases more than 100-fold, for violations of public order at demonstrations, despite warnings from his human rights council that it was an unconstitutional infringement on free assembly.

'The Path Our People Have Chosen'

Police and investigators raided the apartments of Udaltsov, anti-corruption blogger Alexei Navalny and socialite Ksenia Sobchak on Monday, seizing computer drives and discs, photographs and other belongings as armed guards stood outside.

"The authorities are in a panic," Udaltsov told reporters. "They are trying to conduct primitive, repressive actions, but I am sure they'll only achieve the opposite effect. These sorts of searches annoy and outrage people, and people in even greater numbers take to the streets."

News agency Interfax reported that Putin responded to the demonstration by saying: "Such heated discussions are the norm for a free democratic country and that is the path our people has chosen."