Heroism and banditry mingled on Chile's shattered streets as rescuers braved aftershocks digging for survivors and the government sent soldiers and ordered a nighttime curfew to quell looting.
The death toll climbed to 711 in one of the biggest earthquakes in centuries.
In the hard-hit city of Concepcion, firefighters pulling survivors from a toppled apartment block were forced to pause because of tear gas fired to stop looters, who were wheeling off everything from microwave ovens to canned milk at a damaged supermarket across the street.
Efforts to determine the full scope of destruction were undermined by an endless string of terrifying aftershocks that continued to turn buildings into rubble.
Officials said 500,000 houses were destroyed or badly damaged, and President Michele Bachelet said "a growing number" of people were listed as missing.
"We are facing a catastrophe of such unthinkable magnitude that it will require a giant effort" to recover, Ms Bachelet said after meeting for six hours with ministers and generals in La Moneda Palace, itself chipped and cracked.
She signed a decree giving the military control over security in the province of Concepcion, where looters were pillaging supermarkets, gas stations, pharmacies and banks. Men and women hurried away with plastic containers of chicken, beef and sausages.
Virtually every market and supermarket had been looted -- and no food or drinking water could be found. Many people in Concepcion expressed anger at the authorities for not stopping the looting or bringing in supplies. Electricity and water services were out of service.
"We are overwhelmed," a police officer said.
Ms Bachelet said a curfew was being imposed from 9pm to 6am and only security forces and other emergency personnel would be allowed on the streets.
Police vehicles drove around announcing the curfew over loudspeakers.
As nightfall neared, hundreds of people put up tents and huddled around wood fires in parks and the grassy medians of avenues, too fearful to return to their homes amid continuing strong aftershocks.
Ms Bachelet, who leaves office on March 11, said the country would accept some of the offers of aid that have poured in from around the world.
She said Chile needs field hospitals and temporary bridges, water purification plants and damage assessment experts -- as well as rescuers to help relieve workers who have been labouring frantically since the magnitude-8.8 quake struck before dawn on Saturday.
To strip away any need for looting, Ms Bachelet announced that essentials on the shelves of major supermarkets would be given away for free, under the supervision of authorities. Soldiers and police will also distribute food and water, she said.
Although houses, bridges and highways were damaged in Santiago, the national capital, a few flights managed to land at the airport and subway service resumed.
More chaotic was the region to the south, where the shaking was the strongest and where the quake generated waves that lashed coastal settlements, leaving behind sticks, scraps of metal and masonry houses ripped in two.