Frantic search for survivors of Madeira floods

More than 120 other people were injured and an unknown number were missing, possibly swept away or smothered, authorities said, adding that they expected the death toll to rise.

The Foreign Office was last night investigating reports that a Briton was among those unaccounted for.

A "small number" of Britons, understood to be fewer than five, were being treated in hospital, where a spokesman said one British female in her 50s was believed to be missing.

Heavy rain lashed the island yesterday, turning some streets in the capital Funchal into raging rivers of mud, water and debris. The storm – the worst to hit the island since 1993 – also displaced 250 people.

Cars that had been swept downhill by muddy waters had landed, crumpled, on the rooftops of houses downstream. Rescue teams who dug out one car from chocolate brown slime were seen working inside it, possibly to recover more bodies.

The death toll "will likely increase, given the circumstances of this flood", regional social services spokesman Francisco Ramos said, adding that there were "great difficulties" in communications.

Firefighters used pumping equipment to try to drain an underground car park at a downtown department store close to where the heaviest flow of floodwaters descended. Local authorities feared shoppers might have been trapped below ground by the muddy deluge.

"The store is totally destroyed, damaged, full of slurry," said owner Joao Andrade.

The flash floods were so powerful they carved their own paths down mountains and through the city, churning under bridges and even tearing some down. Residents had to cling to railings to make sure they were not swept away. Cars were consumed by the force of the water, and the battered shells of overturned vehicles littered the streets.

Rescue workers helped people cross at some places where the flow of the water wasn't so strong. The water swept even a heavy fire truck downstream, slamming it into a tree, while rescuers on inflatable rafts navigated through streets looking for trapped residents.

The weather improved yesterday, making it easier for rescue workers to move around. But some roads and bridges were washed away and others were littered with uprooted trees, cars and boulders, hampering search and rescue efforts.

Portuguese Prime Minister Jose Socrates said he was "profoundly shocked" by the severity of the floods and promised the government would help Madeira recover as quickly as possible.

A medical team backed up by divers and rescue experts was being sent today aboard a C-130 transport plane to the archipelago, 550 miles south-west of Lisbon.

The plane was also carrying telecommunications equipment, since the flash floods also ripped out phone lines.

Madeira is the main island of a Portuguese archipelago of the same name, in the Atlantic Ocean off the north-west coast of Africa. The island is popular with British tourists.

Army units based on the island mobilised rescue teams, debris removal crews, bridge specialists and two helicopters.

The island's most famous son, Real Madrid football star Cristiano Ronaldo, was horrified by the floods. "Nobody can remain indifferent to the disaster," he told journalists in Madrid.