TONGOY (Chile) • Residents sifted through rubble on Thursday and saved what they could from homes destroyed by a magnitude-8.3 earthquake in central Chile that killed at least 12 people, forced one million from their homes and sent giant waves crashing into coastal areas.

Aftershocks shook the South American country following Wednesday's quake, which was the strongest in the world this year and the biggest to hit Chile since 2010. But some residents expressed relief that the destruction had not been greater.

The northern port city of Coquimbo, where waves of up to 4.5m slammed into the shore, was declared an emergency area by the government. The move gives the government a range of special powers aimed at speeding aid to the city and allowing soldiers to patrol the streets to prevent looting.

Fishing boats washed up onto the streets in Coquimbo while other vessels splintered, littering the bay with debris.

"We lost it all. It was horrible," said 79-year-old resident Hilda Zambra, whose home in Tongoy, a town some 40km south of Coquimbo, was destroyed.

The homes of 610 people were so badly damaged that they were unable to return by late Thursday afternoon, according to government data. Some 179 homes were destroyed, 87,600 were without electricity and 9,000 were without clean water.

The government had ordered evacuations from coastal areas after the earthquake hit, seeking to avoid a repeat of a quake disaster in 2010 when the authorities were slow to warn of a tsunami and more than 500 people were killed.

"We want to thank people for their cooperation, which allowed for a death toll that, while unfortunate, was not very high considering the strength of the earthquake," President Michelle Bachelet said.

The latest quake was felt as far away as Buenos Aires in Argentina.

Ms Bachelet, who said her government "learnt a series of lessons" from previous disasters, began a tour of damaged areas in the town of La Serena, near Coquimbo.

Chile is the world's top copper producer and operations were suspended at two big copper mines as a precaution, sending prices on the London Metal Exchange to two-month highs on concern over disruptions to supplies, although prices dipped later.

Tsunami alerts were issued after Wednesday's quake across the Pacific, from parts of California to Japan and French Polynesia, although waves were expected to be small.

In northern Japan, a minor tsunami was monitored early yesterday morning, the Japanese authorities said. A wave of 30cm was recorded off the Japanese city of Kuji at 7.13am local time, said the Japan Meteorological Agency. It was smaller than the possible 1m tsunami that the agency warned could hit.

In Chile, the tsunami warning was lifted on Thursday morning, but one port used for exporting copper and other natural resources was completely shut down that day. Three others closed for smaller vessels, suggesting that trade flows might be interrupted.

Quake-prone Chile has strict building regulations, so newer buildings are able to withstand even strong quakes.

Chile was due to celebrate its national holiday yesterday, but some roads between Santiago and the north remained cut off.

The earthquake was the latest natural disaster to roil mining in Chile, which accounts for a third of global copper output. Northern Chile was hit by severe floods earlier this year, while a volcanic eruption caused problems for residents in the south.

Chile runs along a highly seismic and volcanic zone where tectonic plates meet, and the country often experiences earthquakes.

REUTERS, AGENCE FRANCE-PRESSE