MEXICO CITY - Hundreds of protesters clashed with police in Mexico City on Saturday, leaving around 30 people injured as Enrique Pena Nieto's swearing in heralded the return of the nation's longtime ruling party.
Around 500 demonstrators, many in masks, threw objects and Molotov cocktails outside Congress, which was surrounded by metal barricades, as street battles raged and police countered with tear gas.
The violence erupted ahead of Enrique Pena Nieto's inauguration ceremony, which completed the path back to power of the Institutional Revolutionary Party (PRI) that ruled Mexico for 71 years until it lost the 2000 election.
One officer was hit in the face by a stone, while two others were struck by a Molotov cocktail. They were taken away in ambulances while two more officers were carried out by their colleagues, apparently affected by the tear gas and one protester appeared to have a head injury.
"We weren't expecting something so violent," an officer told AFP.
More violence erupted near the national palace, where Pena Nieto gave a speech, with police and protesters clashing while looters ransacked shops, restaurants and hotels in the city's historic center.
Around 30 people were injured, including four seriously, according to police and Red Cross accounts. Authorities detained 65 people.
The second-place finisher in this year's election, leftist leader Andres Manuel Lopez Obrador, has refused to concede defeat, charging that the PRI bought millions of votes. But the electoral court threw out his claims.
The group that clashed with police was among thousands of protesters who took to the streets to defy Pena Nieto's inauguration, chanting "Mexico without PRI!"
Inside Congress, some lawmakers held up placards against the new president, a telegenic 46-year-old lawyer and former Mexico state governor.
Leftist legislators unfurled a giant black banner with crosses and the words "Imposition accomplished, Mexico in mourning."
"A spurious government has concluded and the nightmare of imposition, illegitimacy and return to the past begins," Deputy Ricardo Monreal, who was Lopez Obrador's campaign manager, told Congress.
Lopez Obrador had lost the 2006 election to outgoing conservative president Felipe Calderon by less than one point and also refused to accept that defeat.
Six years ago, Lopez Obrador led massive protests that paralyzed Mexico City for weeks but there were far fewer people this time around.
Only hundreds gathered at the Angel of Independence monument for a rally led by Lopez Obrador.
Pena Nieto insists that the PRI -- which governed with a mix of patronage, corruption and repression from 1929 to 2000 -- has embraced democracy and will not return to its dark past.
The new president inherits a brutal drug war that left more than 60,000 people dead during the six-year term of former president Felipe Calderon, who launched a military offensive against organized crime.
Some lawmakers held up a banner that said: "Calderon, you leave a seat bathed in blood."
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