More than 9,000 people were left homeless after a powerful earthquake hit northern and central Chile last week, officials said Sunday, dramatically increasing previous estimates.

The death toll from the 8.3 magnitude quake that struck on September 16 remained at 13, with four still missing, said Deputy Interior Minister Mahmud Aleuy.

Southern Chile remained on alert Friday for another eruption from the Calbuco volcano after it burst into life in spectacular, fiery fashion for the first time in half a century, forcing 5,000 people to evacuate and lighting up the night sky.

Authorities declared a state of emergency, sent in the army and evacuated a 21-kilometer (13-mile) radius around the volcano after the twin eruptions -- the first on Wednesday as night fell and the second early Thursday before sunrise.

Three people were killed and several injured during a concert at a nightclub in downtown Santiago after the building collapsed, authorities said Friday.

Some of the wounded had life-threatening injuries and were sent to the hospital with serious chest and head wounds. 

Chilean police fired tear gas and water cannon Sunday to break up thousands of indigenous protesters demanding land rights and condemning Columbus Day, after masked demonstrators began throwing stones.

The march in Santiago began festively, with demonstrators decked out in colorful clothing and playing traditional indigenous music from around the country.

Fourteen people were wounded and 179 arrested during unrest that broke out on the 41st anniversary of the coup that brought Chilean dictator Augusto Pinochet to power, police said Friday.

The unrest was however less destructive than in previous years' commemorations of the September 11 anniversary, a date that remains deeply divisive in the South American country.

At least 18 people were killed on an Argentine highway Friday when a truck driving on the wrong side of the road crashed head-on into a bus, local authorities said.

Both vehicles immediately burst into flames, leaving twisted metal remains, television images showed. Firefighters were still working on retrieving the charred bodies for identification.