Thousands of Russian ultra-nationalists marched through central Moscow on Sunday vowing to drive Vladimir Putin out of the Kremlin and accusing him of ignoring the rights of ethnic Slavs.
Armed with anti-Putin slogans, Orthodox banners and black-and-yellow flags of pre-revolutionary Russia, the mostly black-clad participants joined in a "Russian March" in Moscow as Putin faces the most vocal opposition to his rule since coming to power 12 years ago.
The march followed by a rally was agreed with the authorities and timed to coincide with the Day of Popular Unity, a national holiday which this year marks the 400th anniversary of the 1612 expulsion of Polish occupiers from the Kremlin.
"Putin's clique to trial," some participants shouted during the annual march. "We beat Hitler, we will beat Putin."
Scores of people were detained at similar but unsanctioned marches in several other cities and in Moscow several dozen people attacked anti-fascist activists.
The Russian president has been facing a nascent protest movement against his rule since he was elected to a third term in May, and the anti-Putin cause has become popular with ultra-nationalists.
Putin himself has slammed attempts to inflame nationalist sentiments, evoking the country's multi-ethnic history.
Accompanied by top representatives of Russia's main religions, Putin on Sunday laid red carnations at the Red Square monument to Kuzma Minin and Dmitry Pozharsky who helped rid Moscow of Poles in 1612, and in a speech at the Kremlin extolled the importance of a strong state.
But Alexander Belov, one of the march's organisers, said an increasing number of people were growing disillusioned with the veteran leader.
"Putin is afraid of us," he told the rally. "He feels his time is ending because the future belongs to us. We will chase out the occupiers from the Kremlin."
He shouted to the crowd: "Putin is a ...", and the rally participants answered "thief and scum," charging his place should be "in prison".
The nationalists have accused Putin of neglecting the rights of the multi-ethnic country's Slavic majority and turning a blind eye to illegal immigration.
Belov estimated the turnout at the march at around 20 000, while Moscow police put the number of participants at up to 6000.
Moscow police detained 25 people wearing black overcoats and marching in the city centre.
It was the first time in several years that the authorities have allowed the march to take place in central Moscow instead of its fringes.
In the Volga city of Kazan, police detained 54 people, while around 70 people were arrested in Saint Petersburg and some 90 were detained in the Urals city of Yekaterinburg.
In Moscow, several dozen young people, presumably neo-Nazis, attacked a group of anti-fascist activists at a metro station in the city centre, injuring several of them, Pavel Samburov, a representative of a gay and lesbian group said, citing friends.
"Someone was thrown at the rails," he told AFP. A Moscow police spokesperson said a minor "scuffle" involving five people had taken place.
The Federation of Migrants of Russia had asked authorities to ban the event, arguing the march could sow discord in the multi-ethnic capital.
But a growing number of Russians sympathise with the nationalist cause.
Many Muscovites complain of a heavy influx of poorly educated migrants from impoverished ex-Soviet Central Asia, saying the affluent capital is already bursting at the seams.
"I am against the lack of a visa regime with Central Asian countries," said Andrei Goldin, a 38-year-old university teacher.
Many observers fear Russia may plunge into chaos if nationalist forces come to power, and some liberal analysts say that compared to ultra-nationalists, Putin may be the lesser of two evils.