The death toll from flash flooding in Spain has risen to 140, according to local media, as rescue teams continue to search flood-ravaged homes and vehicles.

Communities in several regions of Spain are reeling from Tuesday's flooding, with authorities saying many more people are still unaccounted for.

The worst hit region was Valencia, where torrential rain flooded villages and left cars piled on top of each other in the streets.

A storm system dropped a year's worth of rain on some parts of the country on Tuesday.

On Thursday, Spain's national weather service issued further flooding alerts for parts of the country. 

Rescuers on Thursday were using helicopters to winch survivors to safety while diggers and tractors have been brought in to clear debris from streets.

Floodwaters have swept away bridges and could disrupt rail services in the country for days.

"Unfortunately there are dead bodies in some vehicles," Spanish Transport Minister Oscar Puente told Reuters.

Residents have described seeing people clambering onto the roofs of their cars as floodwaters rose.

In some communities, up to three metres of water was flowing through homes.

The system which caused Tuesday's deluge in Valencia has now moved north, with the AEMET state weather agency issuing the highest level of alert to the province of Castellon.

While visiting a rescue coordination centre in Valencia, Prime Minister Pedro Sanchez issued a warning to residents to stay home due to the alerts.

The flooding which hit southern and eastern parts of Spain was triggered by the DANA weather phenomenon, which climate scientists say is becoming more frequent as the climate warns.

It is the worst flooding disaster in Europe since 2021, when 185 people were killed by flooding in Germany.

It is also Spain's deadliest flash floods in modern history.

 Reuters/AP