At least 10 people died, including two Britons, and a boy remained missing Wednesday after flash floods hit the Spanish holiday island of Majorca, tearing through village streets and sweeping away cars.

Muddy waters rushed down roads, houses were flooded and vehicles piled up on top of each other after the Mediterranean island was pounded with rain in just a few hours, video footage showed.

One witness told a local newspaper he had to swim out of his car through a window to safety.

"I swam 500 metres (1,650 feet) through the torrent until I got to a house," Manuel Torrescusa told the Diario de Mallorca.

"I hardly had any clothes on me as they all got caught on a metal fence when I was swimming." Emergency services in the Balearic archipelago tweeted that the death toll had risen to 10 and a little boy remained missing.

Britain's foreign office said two British nationals had died.

"We are supporting the family of two British people following their deaths in Spain, and will do all we can to assist them at this deeply difficult time," it said in a statement.

Emergency services sent out tweets in Spanish, Catalan, English and German in an indication of the prevalence of tourists and foreign residents on the island.

Last year, 13.8 million foreign tourists visited the Balearic Islands, according to official statistics. The biggest numbers came from Germany and Britain. Many more foreigners live in the archipelago.

Spain's meteorological office warned that rainfall and storms were set to get worse in the archipelago "in the coming hours."

In Majorca, the worst affected area lay 60 kilometres (37 miles) east of the capital Palma de Majorca.

Sergio Mantas, a local policeman, told the Diario de Mallorca that the situation in Sant Llorenc des Cardassar, one of the worst-hit villages, had been "devastating." Javier Martinez told the daily he had to leave his flooded home.

"I don't have anything with me, just my pyjamas," he was quoted as saying. "My house filled up completely and when it (the water level) dropped we left and went through the mud that the flood left."

Local television showed footage of beach umbrellas floating in the sea near S'Illot, one of the affected coastal villages.

Around 500 emergency workers were searching for people and helping those affected, the regional government said. Helicopters and search dogs were also sent to the scene, the country's emergency military unit added.

Prime Minister Pedro Sanchez visited the disaster zone and described the situation as "absolutely extraordinary".

He promised financial help for affected zones.

Spanish tennis star Rafael Nadal, who is from the affected area in Majorca, said on Instagram he was offering to open up his sports centre and tennis academy to people made homeless by the floods. "Our most sincere condolences to the loved ones of the victims of the serious floods in San Llorenc," he wrote.

Many people spent the night in sports centres. Maria Magdalena Ferrer, spokeswoman for the Manacor Hospital in the affected area, told AFP that people "who were in the hospital yesterday and weren't able to go home" stayed the night.