Vladimir Putin took office on Monday as Russian president for a historic third term in a glittering Kremlin ceremony shadowed bybloody clashes between police and protesters against his rule.
Putin, president from 2000-2008, took over from outgoing president Dmitry Medvedev after swearing in his oath to protect the rights of Russian citizens and defend the country's integrity.
In the fifth Russian presidential inauguration since the collapse of the Soviet Union, Kremlin bells chimed, the presidential guard donned Tsarist-era uniforms and the orchestra played Tchaikovsky marches.
Placing his hand on a copy of the constitution, Putin swore to "respect and protect the rights and freedoms of the people" and defend Russia's security as he officially took over from Medvedev.
In the lavish ceremony aiming to remind the world of post-Soviet Russia's status as a global power, the outgoing prime minister Putinin a brief speech hailed a "reborn" Russia and promised a new stage in its development.
"Today, we are entering a new stage of national development. We will have to decide tasks of a new level, a new quality and scale. The coming years will be decisive for Russia's fate for decades to come," he said.
Yet activists accuse Putin of sacrificing rights in the pursuit of stability during 12 years of domination over Russia and lacking legitimacy after his knockout March 4 election victory was marred by claims of fraud.
The inauguration was marked by needle-sharp choreography, with Putin driven from the government headquarters through the eerily deserted Moscow streets blocked off by police and then into the Kremlin itself.
The eve of the ceremony saw the worst clashes yet between police and anti-Putin protesters when a mass opposition demonstration descended into chaos and security forces wielded their batons to arrest hundreds of people.
Police said that 436 people were detained at Sunday's protest, including the anti-Putin leaders Alexei Navalny and Sergei Udaltsov who now face the prospect of spending at least the next two weeks in jail.
The authorities said that 20 police were wounded by stones and glass thrown by the protesters, who in turn accused the authorities of responding with heavy -handed tactics to violently disperse the protest.
The Interfax news agency quoted medical sources as saying dozens of protesters had required medical treatment while opposition websites said that up to 650 demonstrators had been arrested.
The bitter clashes were in stark contrast to the winter's mass anti-Putin protests which smashed the taboo against big opposition rallies in Russia but also took place peacefully without any arrests.
A vast security blanket was thrown over Moscow Monday, with police already in the early morning fencing-off squares in the city centre that could potentially be used as protest venues.
Police made a handful of arrests Monday morning as dozens of people wearing the while ribbon that is the symbol of the Russian opposition tried to stage a meeting outside the Kremlin walls, an AFP correspondent reported.
Protest leaders bickered over their future strategy with supporters of the ultra-left wing Udaltsov calling for civil disobedience but liberals expressing disgust over the radical opposition's provocative behaviour.
Medvedev has served as president since 2008 as Putin was constitutionally barred from serving more than two consecutive terms, having become head of state in 2000 following the resignation of Boris Yeltsin.
Putin remained in full charge as he instead took the job of prime minister. Yet analysts say he now faces the unprecedented challenge of a six-year term at a time when Russian society is changing at speed.
Foreign heads of state were not expected at the inauguration, although some former political players such as Italian ex-prime minister Silvio Berlusconi, a friend of Putin, were present.
Medvedev, meanwhile, is expected to take on Putin's old job as prime minister but remain largely in the shadows after his presidency failed to deliver initial promises of political and economic modernisation.