A total of 29 police officers have been injured in clashes with demonstrators that broke out during Sunday’s opposition rally in Moscow, the Moscow police press service reported.

The demonstration, held on the eve of Vladimir Putin's inauguration as president, turned violent after protest leader Sergei Udaltsov led a mass sit-in and demanded to be allowed to march directly to the Kremlin and for Putin’s victory in the disputed March 4 elections to be annulled.

Protesters attacked police with bottles and stones, seriously injuring several officers, who have been hospitalized. Unconfirmed images were posted on the Internet of a number of protesters with what appeared to be serious injuries.

A total of 436 people were detained during the riots, the police press service said. Most of the detainees have been released and ordered to pay administrative fines. Those found guilty of assaulting officers may face up to ten years in prison.

Udaltsov, leader of the Left Front movement, was among those detained, along with anti-corruption activist Alexei Navalny and Boris Nemtsov, opposition leader and Yeltsin-era deputy prime minister.

Some 8,000 protesters took part in the rally, which was authorized for 5,000 people.