Chile's president condemns police violence after four weeks of unrest

President Sebastian Pinera has condemned for the first time what he called abuses committed by police in dealing with four weeks of violent unrest that have rocked Chile.

"There was excessive use of force. Abuses and crimes were committed, and the rights of all were not respected," the president said in a speech on Sunday to the nation as it marked a month of turmoil that has left 22 people dead and more than 2,000 injured.

Furious Chileans have been protesting social and economic inequality, and against an entrenched political elite that comes from a small number of the wealthiest families in the country, among other issues.

Accusations of police brutality and human rights violations have been levelled since the protests broke out, prompting the United Nations to send a team to investigate. Amnesty International has also sent a mission.

"There will be no impunity, not for those who committed acts of unusual violence, nor for those who committed excesses and abuses. We will do what is best for the victims," he said, referring to protesters first and then the security forces.

Pinera also praised an agreement reached last week under which Chile will draft a new constitution to replace the current one that dates back to the rightwing dictatorship of Augusto Pinochet, who ruled from 1973 to 1990.

Many in Chile see this step -- getting rid of a charter that smacks of a dark, repressive chapter in the country's past -- as a way to help end the crisis. It is a key demand of the thousands of protesters that have been taking to the streets in Santiago and elsewhere almost daily for a month.

The spasm of anger began with a rise in metro fares but quickly swelled into a broader outcry against the status quo in what is traditionally considered one of South America's most stable countries.

"If the people want it, we will move toward a new constitution, the first under democracy," Pinera said in a speech from the presidential palace.