Spanish rescuers on Wednesday scrambled to save people trapped by surging tides of muddy water in floods that have killed at least 62 people in the eastern Valencia region.
Prime Minister Pedro Sanchez urged citizens not to lower their guard as the emergency continued and pledged not to "abandon" victims of the disaster on a scale rarely seen in the European country.
Heavy rain and fierce winds have lashed Spain since the beginning of the week, sparking floods in the eastern Valencia and southern Andalusia regions.
Emergency services in Valencia region announced a provisional death toll of 62 on X, adding that bodies were still being recovered and identified.
The number is expected to rise as other regions have yet to report victims.
"Several hundred people" remained trapped on two motorways in Valencia region, according to its fire service chief Jose Miguel Basset.
Parts of the Valencia region are without power and telephone connections while some places were cut off by flooded roads, complicating the rescue efforts, regional president Carlos Mazon told reporters.
Cars lay scattered and piled on top of each other on roads near the Mediterranean coastal city of Valencia after a mudslide, an AFP journalist saw.
Residents tried to clear the sludge from their homes with buckets and waded through waist-high waters in an attempt to save their belongings.
Maria Carmen, a resident of Valencia city, told Spanish public broadcaster TVE she climbed through her car window and sheltered on the roof of a van for hours to escape the floodwater.
Sanchez said the government's "absolute priority" was to help the victims. "All of Spain weeps with all of you... We won't abandon you," he said in a televised address.
The disaster could not be considered over and "we will deploy all the necessary resources for as long as necessary so that we can recover from this tragedy," he added.
King Felipe VI said he was "devastated" by the news on X and offered "heartfelt condolences" to families of the victims, thanking emergency services for their "titanic" response.
The prime minister of neighbouring Portugal, Luis Montenegro, expressed his country's "greatest regret" and "solidarity with all the Spanish people" in a message on X.
Germany's Chancellor Olaf Scholz said he was "shocked" and sent "his sincerest condolences" to the victims' relatives.
The European Union has already activated its Copernicus satellite system to help coordinate Spanish rescue teams, commission chief Ursula von der Leyen told a news conference in Brussels.
The bloc has also offered to use its civil protection mechanism to send further reinforcements, she said.
The central government's representative in the Valencia region, Pilar Bernabe, said emergency military response units were being sent from several regions to reinforce the rescue work.
Defence Minister Margarita Robles told reporters "more than a thousand troops" backed by helicopters were being deployed in the face of "an unprecedented phenomenon".
Emergency services in the Valencia region rescued almost 200 people overnight who were now being sheltered in fire stations, Basset added.
Rail and air transport was severely disrupted and the high-speed line between Valencia and Madrid remained closed.
The Spanish parliament held a minute's silence on Wednesday to honour the victims before a usually raucous session of questions to the government.
The flood toll is the deadliest in Spain since August 1996 when 86 people died in the northeastern region of Aragon near the Pyrenees mountains bordering France.
Meteorologists have said the latest storm was caused by cold air moving over the warm waters of the Mediterranean Sea, which produced intense rain clouds.
The downpours are expected to continue until at least Thursday.
Scientists warn that extreme weather events such as storms are becoming more intense, last longer and occur more frequently as a result of human-induced climate change.
Meteorologists say the warming of the Mediterranean, which increases water evaporation, plays a key role in making torrential rains more severe.
