The welcome sign at the entrance to the town of Constitucion shows beach umbrellas, boats and sun. Plastered outside the town morgue is a list of 51 dead.

In this area famed for its beaches and fish, hundreds of residents and tourists are dead or missing, and police from the Chile Crime Investigation PDI squad foraged Tuesday for corpses washed up on what last year was a prime vacation spot.

As troops and rescue workers move in to this coastal region, the extent of the horror from Saturday's 8.8 magnitude earthquake and a cluster of tsunamis has begun to reveal itself, the army chief in charge of area emergency operations told AFP.

"The force of the tsunami was terrific," said General Bosco Pesse. "Water washed two kilometers (1.2 miles) inland in some places."

In a string of tsunami-hit coastal villages, the toll could double, to more than 1,000, he said. This region, which was closest to the epicenter of the temblor, one of the most powerful on record, already accounts for 587 of the 799 people confirmed dead nationwide.

When the huge waves raged ashore in the early hours of Saturday, beachside restaurants and bars were full in Constitucion. It was the penultimate day of the summer school holidays and crowds had streamed to the beach for a fireworks display set for Sunday.

Nestled at the foot of towering cliffs and a giant stone formation known as the "Piedra de la Iglesia," the resort boasted a walkway, a playground for toddlers, attractions and stalls.

All that remain are tangled tables, mangled cars and refrigerators, and a mass of muddied planks, broken brick walls, twisted steel bars and telegraph poles.

Bits of smashed colored wood in small piles lie where a kiddie park used to be. Debris hangs from trees growing on cliffs some 30 meters (100 feet) above sea level.

A large fishing boat lies in the street, a mystifying scene repeated in several coastal towns and villages raked by the huge waves which obliterated homes and buildings and left many people here in shock.

"It was powerful, I can't believe what I'm seeing," said Miriam Fuentes, a longtime Constitucion resident.

With scores of others, Fuentes is walking about, taking souvenir snapshots much as the vacationers did and trying to make sense of the fury unleashed by mother nature.

"Most of us didn't dare come until today, we're still too scared of another tsunami, of another quake. It's a tragedy to see this beautiful place we loved turned into a disaster zone."

In the ruins of the resort's top restaurant "El Marbello," where a muddy crate stands witness to the past, 50-something owner Artillana Mancilla pledges to rebuild her eatery and her life.

"All I need is some help from the government," she said.

Four days after the massive quake and ensuing tsunami, thousands of troops are moving into place in Chile, generally quiet and well-ordered in spite of shortages and blackouts, but facing pockets of severe violence and rampant looting. Strict curfews are coming into force in major towns.

On the road south linking Constitucion to Concepcion, the country's second largest city, small groups of survivors wave bits of cardboard on flimsy sticks that say "We need food, we need water."

People from Concepcion now are living in tents pitched in the woods, while others crowd the roadside in blazing summer sun hoping for help.

"We're too afraid to go back there, there's a bad smell of corpses and people say there's a risk of infection," said Bernarda Loyola, who walked to the pine-covered hills above the popular seaside resort when her souvenir shop was washed away by giant waves on Saturday.

Machine-guns at the ready, two dozen soldiers stand watch as US aid organisation Samaritan's Purse hands out food parcels to a long quiet queue of needy.

"When people are hungry there's often trouble. Look at Haiti," says the commander, when asked about the show of force.