Chile's President Sebastian Pinera on Monday condemned rioting that disrupted the opening of Latin America's biggest music festival amid fears of a broader return to violence next month in the troubled South American country.

Authorities said 23 police officers were injured in clashes when rioters looted around 30 stores, torched vehicles and forced the evacuation of a hotel in the coastal resort of Vina del Mar.

"Chile has already had too much violence," Pinera said after a cabinet meeting Monday, his first since returning from vacation.

"We need to ensure public order and live in peace to have a plebiscite that is democratic, clean and transparent," said Pinera, referring to an April 26 referendum to update the dictatorship-era constitution.

"The time has come for a great agreement for democracy, against violence and for peace," the president said.

A policeman is seen near torched cars during a protest Sunday against Chilean President Sebastian Pinera's government in music festival venue Vina del Mar
A policeman is seen near torched cars during a protest Sunday against Chilean President Sebastian Pinera's government in music festival venue Vina del Mar AFP / MARTIN BERNETTI

The referendum was one of several concessions made by conservative Pinera to quell a four-month wave of protests over economic inequality that ignited across Chile in October.

The Vina del Mar festival was a tentative return to normality after an atmosphere of violence forced the government to cancel several other major events, including November's COP 25 climate change conference.

Instead, thousands of protesters armed with stones, sticks and Molotov cocktails clashed with police near the festival venue, a resort about 120 kilometers (75 miles) west of Santiago.

Riot police, backed by a helicopter and a balloon with surveillance cameras, drove back the protesters with water cannon and tear gas.

Demonstrators clash with the police in Vina del Mar on Sunday
Demonstrators clash with the police in Vina del Mar on Sunday AFP / Martin BERNETTI

After failing to get into the festival grounds, protesters attacked nearby shops and the renowned O'Higgins Hotel, forcing the evacuation of the guests, who included some of the artists expecting to perform at the festival.

"Yesterday, Vina del Mar was brutally attacked by criminals. I have called on the interior ministry to ensure the safety of the city," said the city's mayor Virginia Reginato, as authorities said security would be beefed-up for the rest of the festival.

Multiple Grammy-winner Ricky Martin opened the show. After a two-hour set, he asked Chileans not to remain silent and to demand what they deserve with "love and peace."

"That (Chileans) express themselves, that they demand the basics, human rights, is basic, we don't ask for anything. I am with you Chile, never silent, always with love and peace," said the 48-year-old Puerto Rican singer.

With the annual Vina del Mar festival something of a test-bed for social mood after a lull in the protests, authorities fear a new round of protests next month when the summer holiday season ends.

Protest organizers have circulated a calendar of marches, including March 8th, International Women's Day, and March 29, when Chileans commemorate the deaths of two brothers murdered by the Pinochet dictatorship.

Pinera himself sounded a note of apprehension Saturday on Twitter, even before the latest violence.

"March: will it be a month of agreements or violence? Many people are anticipating a violent March," wrote the under-fire president, whose public disapproval rating has soared to 83 percent.

"The government has prepared to safeguard public order and promote a March of agreements."

"Agreements and non-violence is the way."