A bridge between two cities in central Santa Fe province collapsed because a rain-swollen river weakened its foundation.

In Buenos Aires province, Argentina's most populous, some 3,500 people remained displaced from their homes because of flooding from Monday's storm, provincial official Luciano Timerman said.

In just six hours the province got nearly as much rain as it does in an entire average month of October, the national weather service said.

In Buenos Aires itself, avenues were flooded and train and subway services were knocked out. Large areas of the city of three million suffered blackouts.

Winds gusting at up to 110 kilometers per hour (65 miles per hour) tore the roofs off homes in the town of Rio Tala, injuring around 10 people.