Seven hours of nonstop downpours left the city of 350,000 people -- located 600 kilometers (about 375 miles) south of the capital Buenos Aires -- largely under water, and forced authorities to evacuate the Jose Penna hospital.

Television images showed medical personnel evacuating babies from the hospital's neonatal unit, and the army was deployed to assist in the city's rescue efforts.

In all, around 1,000 people were brought to safety.

Bahia Blanca's airport was closed until further notice.

The provincial government said it was sending helicopters, canoes, ambulances and trucks bearing food, water and equipment to the stricken city.

Argentina's defense and security ministers were en route to the city to assess the situation.