Around 100 people were injured and nearly 100 others arrested in clashes between police and protesters angry over the inauguration of new President Enrique Peña Nieto in Mexico City, officials said.

A total of 92 people, including 11 minors, were taken before prosecutors following the violence on Saturday, Mexico City Mayor Marcelo Ebrard said in a press conference.

Of those arrested, 72 are males and the rest females, the mayor said.

The violence was the work of groups that planned the incidents in an effort to affect the stability of the capital, Ebrard said.

"What does this have to do with what was happening at San Lazaro?" Ebrard asked, referring to Peña Nieto's swearing-in ceremony at the seat of Congress.

"If anyone is disgusted, it is Mexico City because of this aggression, and it is not going to go unpunished," the mayor, a member of the leftist Party of the Democratic Revolution, or PRD, said.

Federal District Attorney Jesus Rodriguez, meanwhile, blamed anarchist groups for the violence and vowed to investigate whether other groups were involved.

Peña Nieto was inaugurated on Saturday as Mexico's president, returning the Institutional Revolutionary Party, or PRI, to power after a 12-year hiatus.

Outgoing President Felipe Calderon kissed the presidential sash before handing it over to his successor amid cries by legislators in favor and against Peña Nieto, a telegenic former governor of the central state of Mexico.

In the chamber of the lower house, where the ceremony was held, a large banner was carried by opposition lawmakers with crosses of mourning that said "Imposition accomplished, Mexico in mourning," referring to the left's claims that Peña Nieto's victory in the July election was due to widespread electoral fraud.

Some 60,000 people died in drug-related violence during the six-year presidency of Calderon, who militarized the struggle against Mexico's violent, well-funded cartels by deploying tens of thousands of army soldiers to drug-war hotspots.

The PRI, which governed Mexico from 1929 to 2000, lost the 2000 presidential election to the National Action Party, or PAN, and finished third in 2006.

During its 71-year reign - described by Peruvian Nobel literature laureate Mario Vargas Llosa as the "perfect dictatorship" - the PRI relied mainly on patronage and control of organized labor and the mass media, though it was not above resorting to outright vote-rigging and even violence. EFE