The help includes cash from the United States, United Nations, Red Cross and European Union as well as tents, water, medicine and other supplies. The U.S. Navy hospital ship Comfort, equipped with a staff of 800 and 12 operating rooms, is in Ecuador and could quickly sail to Peru if asked, U.S. officials said.

In Washington, President Bush offered condolences and said the administration 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.

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 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.

In general, magnitude 8 quakes are capable of causing tremendous damage. Quakes of magnitude 2.5 to 3 are the smallest generally felt, and every increase of one number on the magnitude scale means that the quake's magnitude is 10 times as great.

The temblor occurred in one of the most seismically active regions in the world at the boundary where the Nazca and South American tectonic plates meet. The plates are moving together at a rate of 3 inches a year, Earle said.

The last time a quake of magnitude 7.0 or larger struck Peru was in September 2005, when a 7.5-magnitude earthquake rocked the country's northern jungle, killing four people. In 2001, a 7.9-magnitude quake struck near the southern Andean city of Arequipa, killing 71.