PISCO (AFP) - Rescue teams in Peru's shattered earthquake zone were heading home Monday, as search operations were replaced by stepped-up aid efforts and security patrols against looters.
Wednesday's powerful magnitude-8.0 temblor killed at least 503 people, and the final toll "could reach 540," Civil Defense officials said. Some 1,600 people were injured.
Most of the deaths occurred in the town of Pisco, 240 kilometres (150 miles) south of the capital Lima.
There, 308 people were confirmed killed -- 160 of them in the town's church, which collapsed during mass.
National police colonel Roger Torres told AFP a further 150 were believed still buried in rubble elswehere in Pisco, an evaluation backed by the odor of decomposing bodies hanging heavy in many streets.
President Alan Garcia, on Sunday making his third visit to the town, raged against the looting and assualts reported in several affected areas and said he would restore order "whatever the cost".
"I have ordered to use the harshest measures and if needed to impose a curfew," he told reporters.
More than 1,000 troops and police armed with assault rifles were patrolling the streets of Pisco, 70 percent of which was destroyed.
As security forces were reinforced, teams involved in search and rescue were packing up and going home. Any hope of finding more survivors was now extinguished.
"The possibility of finding someone alive is nearly nil," Jorge Molina, search and rescue operations chief for the local firefighters, told AFP.
An offer of yet another rescue team, from Mexico, was rejected by Peru, which instead asked for food, tents, medecine, clothing and water for the estimated 200,000 people left homeless.
A Mexican hospital ship carrying tonnes of such aid left Sunday for the Peruvian port of San Martin, which it was expected to reach a week later.
Argentina also sent 20 tonnes of similar cargo by plane, and a specialised disaster management team, while Spain sent another plane with 30 tonnes of aid.
Meanwhile, a mass grave was being dug at Pisco's cemetery as an "emergency measure," police officer Jose Sanchez told AFP.
Aid workers were also worried of the risk of an outbreak of disease in the town.
Health Minister Carlos Vallejos said some 1,500 doctors and nurses were struggling to prevent the spread of epidemics among earthquake victims.
"The problem is not only that there are still unfound bodies, the problem is water," and how human waste is being disposed of, he said.
There were fears of an outbreak of infectious diseases in the quake-stricken areas such as diarrhea and cholera, while a choking dust from the rubble of the town was causing respiratory problems.
A field hospital was set up by a small team of US military doctors in the grounds of the Pisco football stadium to try to minimize that danger.
Among aid from other countries, the French embassy in Lima said firefighters from France had arrived in Peru to help.
Aftershocks also continued to keep people on edge. Peru's geophysical institute has reported more than 480 tremors following the quake, which was the most devastating to hit the country since 1970.
Pope Benedict XVI said he would send his secretary of state to Peru, a deeply Catholic country, to convey his personal message on the catastrophe.
US President George W. Bush telephoned Garcia on Sunday to express his concern for and solidarity with the Peruvian people.
Colombian President Alvaro Uribe visited Pisco on Sunday morning and attended a meeting of ministers and emergency workers along with Garcia.
The disaster was set to hit Peru's agriculture and tourism sectors hard. The chamber of commerce for the quake-hit region said 90 percent of industry there was paralyzed, especially wine-growing activities.