LONDON -- Strong winds, heavy rain, and flooding brought by Storm Bert caused travel disruption and power outages across the United Kingdom (UK) over the weekend, leaving three men dead.

The fatalities occurred in road incidents during the storm in Hampshire, Lancashire, and Trefriw, North Wales.

In South Wales, hundreds of properties were inundated. The governing body for Rhondda Cynon Taf, one of the principal areas of Wales, declared a "major incident" on Sunday morning, citing "significant flooding" throughout the region.

Natural Resources Wales issued two severe flood warnings on Sunday afternoon for the River Monnow at Forge Road, Osbaston, and Skenfrith, warning of a danger to life.

Over 100 flood warnings and 200 flood alerts remain active across the UK.

Travel was severely disrupted, with around 200 flights canceled on Sunday at London's Heathrow Airport. Rail services were also disrupted across multiple routes and the National Rail warned that "severe weather may affect parts of England, Wales and Scotland until Monday."

Power outages were reported in parts of England and Wales over the weekend, leaving thousands without electricity during the storm's peak.

In Ireland, Storm Bert also wreaked havoc, causing severe flooding and cutting power to tens of thousands of homes.