Violent weather brought on by Storm Claudia killed three people and injured dozens in Portugal, authorities there said on Saturday, while in Britain rescue workers were organising evacuations due to heavy flooding in Wales and England.

Portugal and parts of neighbouring Spain have faced days of extreme conditions brought on by Storm Claudia, which had reached parts of Britain and Ireland by Saturday.

Rescue workers found the bodies of an elderly couple inside their flooded home in Fernao Ferro, across the River Tagus from Lisbon, on Thursday. They had apparently been sleeping and were unable to flee as the water rose during the night.

On Saturday, a tornado struck Albufeira in southern Portugal, emergency services said.

Footage shot from a distance that was posted online showed the tornado damaging and destroying caravans at a camping area, where regional civil protection commander Vitor Vaz Pinto said an 85-year-old British woman was killed.

Twenty-eight people were injured at a nearby hotel, he said, adding that two of them were in hospital with serious injuries.

In a statement on Saturday, Portugal's President Marcelo Rebelo de Sousa expressed "his solidarity with the family of the victim who died" in Albufeira and wished a speedy recovery to those injured.

Portuguese weather service IPMA placed the entire Algarve and districts of Beja and Setubal on amber alert, its second-highest alert level.

STORM CLAUDIA CAUSES FLOODING IN WALES, ENGLAND

In Britain, severe flooding hit the town of Monmouth and surrounding areas in southeastern Wales on Saturday.

South Wales Fire and Rescue Service said it was conducting rescues, evacuations, and welfare checks.

"Storm Claudia has caused significant flooding in parts of Wales overnight, which continues to affect homes, businesses, transport and energy infrastructure," a spokesperson for the Welsh government said.

Aerial footage showed widespread flooding in Monmouth, with water inundating the town centre and residential areas after a nearby river burst its banks overnight.

Natural Resources Wales has issued 11 flood warnings, four of which are severe, as well as 17 flood alerts.

In England, according to the Environment Agency's latest update, there were 49 active flood warnings and 134 flood alerts.