At least 46 people died Wednesday in and around the city of La Plata, about 37 miles (60 kilometers) southwest of Buenos Aires, Governor Daniel Scioli said. At least six people were reported dead in the capital a day earlier.

"The bodies began to appear as the water subsided," said Scioli.

News of the fatalities prompted the government to declare three days of mourning.

A record 16 inches (40 centimeters) of rain fell on La Plata during a two-hour period late Monday and early Tuesday. In Buenos Aires, six inches (15 centimeters) fell between Monday and Tuesday, the national service said. In some areas, the flood water reached heights of six feet (two meters), with residents climbing onto rooftops or trees to escape the raging rivers.

"Such intense rain in so little time has left many people trapped in their cars, in the streets, in some cases electrocuted," Scioli said. "We are giving priority to rescuing people who have been stuck in trees or on the roofs of their homes."

At least 2,500 people have been evacuated from their homes and the flooding has threatened to ruin food supplies across the La Plata metropolitan area, which has a population of nearly 1 million people.

National Planning Minister Julio de Video estimated that 280,000 people remain without power in the capital area.

"Our job is focused on restoring service, but we're going to wait until equipment dries to guarantee the safety of the electricity workers, because we don't want any deaths," De Vido said.

Argentina's largest refinery in La Plata was also flooded, causing a fire that took hours to extinguish. Argentina's YPF oil company said the blaze was caused by "an extraordinary accumulation of rainwater and power outages in the entire refinery complex."

President Cristina Fernandez traveled by helicopter to the La Plata neighborhood of Tolosa, where she was raised and where her mother was among those evacuated. She announced three days of national mourning for the victims, as well as security measures to curb vandalism and help for identifying the dead.

Around four more inches (10 centimeters) of rain is expected before the bad weather passes on Thursday, according to the national weather service.

dr/jm (AP, AFP, dpa, Reuters)