Vladimir Putin has been sworn-in as president of Russia for a third term.
He is returning to the presidency after an absence of four years in which he served as prime minister. Outgoing president Dmitry Medvedev was widely seen as an ally of Mr Putin, the BBC reports.
Mr Putin won a third term as president in controversial elections in March this year.
On Sunday, thousands of protesters opposed to the inauguration clashed with police in Moscow.
Mr Putin took the presidential oath in a lavish ceremony at the Grand Kremlin Palace on Monday in a hall that was once the throne room of the Russian tsars.
In a short speech he said the country was "entering a new phase 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."
Mr Putin said Mr Medvedev had given a new impulse to modernisation and the "transformation" of Russia must continue.
He also spoke of the need to strengthen Russian democracy and constitutional rights.