By MICHAEL WARREN and EVA VERGARA Associated Press Writers

Mar 1, 2010, 9:52 AM EST

CONCEPCION, Chile (AP) --

Security forces said they arrested dozens of people for violating an anti-looting curfew and rescuers found signs of life in a toppled building on Monday as Chilean officials struggled to bring aid to victims of a quake that killed more than 700 people.

"We are confronting an emergency without parallel in Chile's history," Bachelet declared Sunday, a day after the magnitude-8.8 quake - one of the biggest in centuries - killed at least 708 people and destroyed or badly damaged 500,000 homes.

Some coastal towns were almost obliterated, first shaken by the quake, then slammed by a tsunami that lifted whole houses and carried them inland and that reduced others to piles of sticks.

In Concepcion, the big city closest to the epicenter, police chief Eliecer Soler said officers arrested 55 people for violating a curfew imposed after looters sacked nearly market in town. The first of thousands of troops dispatched to maintain order began to arrive.

Across the highway from a looted supermarket, rescuers heard the knock of trapped victims inside a toppled 70-unit apartment building began to drill holes through thick walls trying to reach them, said fire department Commander Juan Carlos Subercaseux.

Firefighters had already pulled 25 survivors from the building, as well as eight people who died.

Only the chop of military helicopters flying overhead broke the silence demanded by rescuers straining to hear signs of life within the building.

At least a few looters re-emerged to rob a market on Monday despite Bachelet's order placing the city's security under military command.

On Sunday, ingenious looters used long tubes of bamboo and plastic to siphon gasoline from underground tanks at a closed gasoline station.

Eduardo Aundez, a Spanish professor, watched with disgust as a soldier patiently waited for looters to rummage through a downtown store, then lobbed two tear gas canisters into the rubble to get them out.

"I feel abandoned" by authorities, he said. "We believe the government didn't take the necessary measures in time, and now supplies of food and water are going to be much more complicated."

Looters even carted off pieces of a copper statue of South American independence fighter Bernardo O'Higgins next to a justice building.

Efforts to determine the full scope of destruction were undermined by an endless string of terrifying aftershocks that turned more buildings into rubble - and forced thousands to set up tents in parks and grassy highway medians.

"If you're inside your house, the furniture moves," said Monica Aviles, pulling a shawl around her shoulders to ward off the cold as she sat next to a fire across the street from her apartment building.

As if to punctuate her fear, an aftershock set off shuddering and groaning sounds for blocks around.

"That's why we're here," she said.

In another part of the city, eight Peruvian families shared a four-story building - the bravest living inside the cracked building, the others in tents out front.

"We've received help from the neighbors, from passing taxis and from other people who have offered us a coat or something to eat," said Samantha Fernandez, who offered space to boyfriend Jose Luis Jacinto after he fled his room during after the quake.

Bachelet ordered troops to help deliver food, water and blankets and clear rubble from roads, and she urged power companies to restore service first to hospitals, health clinics and shelters. Field hospitals were planned for hard-hit Concepcion, Talca and Curico.

Bachelet also ordered authorities to quickly identify the dead and return them to their families to ensure "the dignified burials that they deserve."

The U.N. said Monday that it would begin rushing aid deliveries to Chile following Bachelet's announcement she was seeking international aid.

U.N. humanitarian spokeswoman Elisabeth Byrs said Chile was seeking temporary bridges, field hospitals, satellite phones, electric generators, damage assessment teams, water purification systems, field kitchens and dialysis centers.

"We are prepared to provide assistance," Byrs told The Associated Press in Geneva. "It could be quite fast, given that our experts are on standby and were alerted in the region."

Defense Minister Francisco Vidal acknowledged the navy made a mistake by not immediately activating a tsunami warning after the quake hit before dawn Saturday. Port captains in several coastal towns did, saving what Vidal called hundreds of lives.

Thirty minutes passed between the quake and a wave that inundated coastal towns, leaving behind sticks, scraps of metal and masonry houses ripped in two. A beachside carnival in the village of Lloca was swamped in the tsunami. A carousel was twisted on its side and a Ferris wheel rose above the muddy wreckage.

Officials said at least eight people died and eight were missing on Robinson Crusoe Island, where it the tsunami drove the sea almost 2 miles (3 kilometers) into the town of San Juan Bautista.

In Washington, the State Department urged Americans to avoid tourist and other nonessential travel to Chile. U.S. citizens in Chile were asked to contact family and friends in the United States, whether by telephone, Internet or cell-phone text messaging.

However Secretary of State Hillary Rodham Clinton planned to briefly visit Santiago on Tuesday as part of a five-nation Latin America trip.

---

Associated Press writers Eduardo Gallardo in Concepcion and Carlos Cisternas in Santiago contributed to this report.