Authorities in Peru say the intense rains, overflowing rivers, mudslides and flooding in the country are the worst in two decades.
Prime Minister Fernando Zavala updated the number of dead from the flooding to 72 since the beginning of the year.
The highly unusual rains follow a series of storms that have struck hard along Peru's northern coast, with voracious waters inundating hospitals and isolating some small villages.
The storms are being caused by a warming of Pacific Ocean surface water. They are expected to continue for another two weeks, with the disaster affecting more than half the nation.
Peru's government said 374 people were killed in 1998 during a similar period of massive rains and flooding blamed on the El Niño climate pattern.
Fumigation targets dengue-carrying mosquitoes
The rains overwhelmed drainage systems in cities along Peru's Pacific coast. The health ministry started fumigating around pools of water that formed in the streets to kill mosquitoes that carry diseases like dengue.
Lima has been without a water service since the beginning of the week.
The government deployed the armed forces to help police control public order in the 811 cities that declared an emergency.
The government acknowledged prices shot up some 5 per cent because of the flooding.
"The prices for lemons have gone up, as well as for potatoes and cooking oil," said Sara Arevalo, a mother of five who was shopping at a market in northern Lima.
Inmates escape juvenile detention centre
In the Lambayeque region, 22 inmates at a juvenile detention centre took advantage of the rains to escape.
Rains flooded a cemetery in the city of Trujillo with the waters carrying bones through the streets.
In Peru's capital city of Lima, where a desert climate seldom leads to rain, police on Friday helped hundreds of residents in an outer neighbourhood cross a flooded road by sending them one-by-one along a rope through choppy waters.
The muddy current channelled down the street after a major river overflowed. Some residents left their homes with a single plastic bag of belongings.
The presidents of Chile, Bolivia and Venezuela offered to send help to Peru.