In Washington, President Bush offered condolences and said the U.S. was studying how best to send help. One American died in the quake, according to the State Department.

Electricity, water and phone service were down in much of southern Peru. The government rushed police, soldiers and doctors to the area, but traffic was paralyzed by giant cracks and fallen power lines on the Panamerican Highway. Large boulders also blocked Peru's Central Highway to the Andes mountains.

Many people said they had seen "lights in the sky," a phenomenon authorities attributed to short circuits at electrical plants where the quake damaged cables and other equipment.

In Chincha, a small town near Pisco only 25 miles from the quake's epicenter, an AP Television News cameraman counted 30 bodies in a hospital patio. The face of one victim was uncovered, her eyes open. The feet of another stuck out from under a blanket.

Hundreds of injured lay side-by-side on cots on walkways and in gardens outside hospital buildings, kept outside for fear that aftershocks could topple the cracked walls.

"Our services are saturated and half of the hospital has collapsed," Dr. Huber Malma said as he single-handedly attended to dozens of patients.

The quake toppled a wall in Chincha's prison, allowing at least 600 prisoners to flee. Only 29 had been recaptured, national prisons official Manuel Aguilar said.

Overstretched police and rescue workers in orange uniforms sought to help survivors trying to get some sleep in the streets amid collapsed adobe homes.

"We're all frightened to return to our houses," Maria Cortez said, staring vacantly at the half of her house that was still standing.

The Peruvian Red Cross arrived in Ica and Pisco 7 1/2 hours after the initial quake, about three times as long as it would normally have taken because of road damage, Red Cross official Giorgio Ferrario said.

In Lima, 95 miles from the epicenter, only one death was recorded. But the furious two minutes of shaking prompted thousands to flee into the streets and sleep in public parks.

"The earth moved differently this time. It made waves and the earth was like jelly," said Antony Falconi, 27, trying to find a bus to take him home.

Scientists said the quake was a "megathrust" — a type of earthquake similar to the catastrophic Indian Ocean temblor in 2004 that generated deadly tsunami waves. "Megathrusts produce the largest earthquakes on the planet," said USGS geophysicist Paul Earle.

Wednesday's quake caused a tsunami as well, but scientists expected surges of no more than 1.6 feet in faraway Japan.