Catastrophic flash floods have killed 57 people in the province of Buenos Aires, while hundreds more remain homeless, officials say.
The worst hit is the city of La Plata, where 51 people died. Six people also died in the capital Buenos Aires.
Many victims drowned as they tried to scramble to safety on rooftops and treetops and some were electrocuted.
The government declared three days of national mourning after what it called "an unprecedented catastrophe".
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Some 100,000 households were destroyed by the floods, La Plata mayor Pablo Bruera said.
Although the torrential rains have stopped and the waters completely receded, power lines are yet to be restored.
Hundreds of government workers are distributing water, food supplies and clothing at dozens of shelters across the province.
Rescue workers canvassed 5,940 homes in La Plata "without any new fatal victims found", Buenos Aires province governor Daniel Scioli confirmed.
Officials had said last Thursday they were still looking for about 20 missing people.
Mobile hospitals have been opened and hepatitis shots are being administered at evacuation centres.
So far more than 40 of the victims in La Plata, about 60km (40 miles) south of the capital, have been identified.
Provincial officials said 40cm (16in) of rain fell on La Plata in the space of two hours late on Tuesday night.
Earlier, the storm dumped 15cm of rainfall on the capital, Buenos Aires.
"We've never seen anything like it," said provincial governor Daniel Scioli.
"People were taken by surprise, and some didn't have time to escape this deadly trap."
More than 3,000 people had to leave their homes and 80,000 lost electricity, with two of La Plata's hospitals also affected by the power cuts.
Some of La Plata's residents set up roadblocks to protect their neighbourhoods from looters.
Last Wednesday, President Cristina Fernandez de Kirchner visited Tolosa, the worst-hit area of La Plata, where she grew up and where her mother still lives.
Ms Fernandez acknowledged residents' fears and promised to increase security.
Before her arrival, dozens of people had looted a supermarket. Three police officers were injured in scuffles with people trying to break into two other supermarkets. — BBC