A man wearing a chef's hat runs for cover as anti-government protesters clash with police in Valparaiso, Chile, Thursday, Oct. 24, 2019. President Sebastian Pinera made more economic concessions Thursday announcing a freeze on a 9.2% rise in electricity prices until the end of next year, to try to curb a week of deadly protests over price increases and other grievances. (AP Photo/Matias Delacroix)

SANTIAGO, Chile (AP) — A new round of clashes broke out Thursday as demonstrators returned to Chile's streets, dissatisfied with economic concessions announced by the government in a bid to curb a week of deadly violence.

Stone-throwing protesters did battle with police firing tear gas and water cannons in the capital, Santiago, and the port of Valparaiso, as hundreds of demonstrators gathered in city squares around the country. Clashes continued into the night.

At least 18 people have died in the turmoil that has swept the South American nation, where the unrest began as a protest over a 4-cent increase in subway fares and soon morphed into a larger movement over growing inequality in one of Latin America's wealthiest countries.

"We don't know who is behind the protests, and not even the government has much idea," said Marcelo Mella, a political analyst at the University of Santiago of Chile.

Mella said there are various factions involved, including a violent group on Santiago's outskirts that follows an "old logic" of Marxist and anti-establishment thought; a poor, angry sector based in the center of the capital; and a more affluent crowd around the city's Plaza Nunoa area.

Most of the demonstrations have been peaceful, but instances of arson, looting and alleged brutality by security forces have shocked many in a nation known for relative stability.

More than 2,000 people have been detained and over 500 injured, according to Chile's human rights watchdog.

President Sebastián Piñera's administration is struggling to contain the strife, announcing increases in the minimum wage and the lowest state pensions, rolling back the subway fare increase and putting a 9.2% increase in electricity prices on hold until the end of next year.

Some protesters have described the economic concessions as too little, too late.

Patricia Bravo, owner of a motorbike repair shop, said the concessions would do little to ease pressure on elderly people with meager pensions and the young, including her two children.

"What future am I going to give them?" Bravo said.

Piñera acknowledged that the steps taken to ease public anger won't fully address the grievances of many people in the country of 18 million. "But we also know that it constitutes important relief," he said.

He gave assurances that Cabinet ministers will contact different sectors of society to hear "the voice and message that Chileans have been sending to us in recent days."

While Piñera was democratically elected to lead a civilian government, the spectacle of soldiers on Chile's streets in recent days has stirred ugly memories of a darker time in the country's history: the dictatorship of Gen. Augusto Pinochet between 1973 and 1990, when about 40,000 people were killed, tortured or imprisoned for political reasons.

Michelle Bachelet, Piñera's predecessor as president and now the U.N. human rights chief, said she would send a "verification mission" to assess allegations of human rights violations in Chile.

In the past few days, millions of students were unable to attend classes, several subway stations were shut, and long lines wound from gas stations and supermarkets after many stores were torched or otherwise destroyed.

The involvement of multiple sectors of society, including students and workers, poses a complex challenge for a government that says it is hard-pressed to deal with rising oil prices and a weaker currency.

Mella, the analyst, said it would be difficult for Chile's "technocratic" government, which favors less state intervention, to negotiate solutions with a protest movement that has no clear leaders.

Protesters view Piñera, who built a huge fortune in business, as a symbol of the political elites they see as exempt from the economic pressures of daily life.

The protesters have demanded improvements in education, health care and wages. Education, medicine and water in Chile are costly, and many families live on just $550 to $700 a month in earnings.

César Millar Sáez, a retiree, criticized the looting and vandalism of the past days but said it is essential to protest for higher pensions and wages.

María López, who works at a home for the elderly, said the same thing. The government's concessions, she said, are not enough.

An anti-government protester stands in front of a burning barricade in Valparaiso, Chile, Thursday, Oct. 24, 2019. President Sebastian Pinera made more economic concessions Thursday announcing a freeze on a 9.2% rise in electricity prices until the end of next year, to try to curb a week of deadly protests over price increases and other grievances. (AP Photo/Matias Delacroix)
A protester is detained by police during an anti-government protest in Santiago, Chile, Thursday, Oct. 24, 2019. A new round of clashes broke out as demonstrators returned to the streets, dissatisfied with economic concessions announced by the government in a bid to curb a week of deadly violence. (AP Photo/Rodrigo Abd)
Soldiers patrol the streets of Valparaiso, Chile, Thursday, Oct. 24, 2019. A new round of clashes broke out Thursday as demonstrators returned to the streets, dissatisfied with economic concessions announced by the government in a bid to curb a week of deadly violence. (AP Photo/Matias Delacroix)
Police detain a man in front of a looted store in Valparaiso, Chile, Thursday, Oct. 24, 2019. A new round of clashes and looting broke out Thursday as demonstrators returned to the streets, dissatisfied with economic concessions announced by the government in a bid to curb a week of deadly violence. (AP Photo/Matias Delacroix)
Chile's President Sebastian Pinera addresses the nation, in Santiago, Chile, Thursday, Oct. 24, 2019. Chile has been facing days of unrest, triggered by a relatively minor increase in subway fares. The protests have shaken a nation noted for economic stability over the past decades, which has seen steadily declining poverty despite persistent high rates of inequality. (AP Photo/Esteban Felix)
People line up to get cash, and pay bills, at a multi-service store, after days of turmoil and protests in Santiago, Chile, Thursday, Oct. 24, 2019. Chile has been facing days of unrest, triggered by a relatively minor increase in subway fares. The protests have shaken a nation noted for economic stability over the past decades, which has seen steadily declining poverty despite persistent high rates of inequality. (AP Photo/Esteban Felix)
People line up outside a supermarket to buy groceries and food, after days of turmoil and protests in Santiago, Chile, Thursday, Oct. 24, 2019. Chile has been facing days of unrest, triggered by a relatively minor increase in subway fares. The protests have shaken a nation noted for economic stability over the past decades, which has seen steadily declining poverty despite persistent high rates of inequality. (AP Photo/Esteban Felix)
A police officer aims pepper spray at a protester, as a stone flies through the air, to disperse anti-government demonstrators in Santiago, Chile, Thursday, Oct. 24, 2019. The protest sign at left reads in Spanish
A roadblock burns near closed shops, one covered with the Spanish message
Neighbors guard the Franklin commercial area to protect it from looters in Santiago, Chile, Thursday, Oct. 24, 2019. The signs read in Spanish
A demonstrator asks a police officer to stop dispersing anti-government protesters in Santiago, Chile, Thursday, Oct. 24, 2019. A new round of clashes and looting broke out Thursday as demonstrators returned to the streets, dissatisfied with economic concessions announced by the government in a bid to curb a week of deadly violence. (AP Photo/Rodrigo Abd)
Protesters use metal sheets as shields during clashes with police during anti-government protests in Santiago, Chile, Thursday, Oct. 24, 2019. A new round of clashes and looting broke out Thursday as demonstrators returned to the streets, dissatisfied with economic concessions announced by the government in a bid to curb a week of deadly violence. (AP Photo/Rodrigo Abd)