Chilean President Sebastian Pinera has said there will be "no impunity" for security forces who violated the rights of protesters.

Violent riots over inequality and economic policies have gripped the South American country for the past month. At least 22 people have died and hundreds have been injured in the turmoil.

"Despite our firm commitment and precautions ... to protect human rights, in some cases protocols were not adhered to," Pinera said in a televised speech to the nation on Sunday night.

"There was excessive use of force. Abuses and crimes were committed, and the rights of all were not respected."

Read more: Opinion: Chile's constitution must come quicker than planned

Public prosecutors in Chile are investigating more than 1,000 cases of alleged abuses by police and the military, including instances of torture and sexual violence. The United Nations and human rights organization Amnesty International have also sent teams to investigate.

New constitution

The protests began last month after the government raised the price of metro fares. The backlash forced Pinera to drop the hikes, but by that point the discontent had ballooned into demands for his resignation and wider social reforms.

In a bid to assuage public anger, Pinera has since announced higher taxes for the rich and increases to the minimum wage and pensions.

Read more: Chile protests: 'It's about 30 years of abuse of power'

On Friday, lawmakers also announced plans to hold a referendum in April 2020 to replace the country's constitution — one of the protesters' key demands.

"Our citizens will now have the last word with respect to a new constitution, the first to be drawn up in democracy," Pinera said in his speech.

The current charter dates back to the 1973-1990 military rule of dictator Augusto Pinochet.

nm/kl (AFP, Reuters)

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