The basement of Liberal Democrat AM Kirsty Williams’ office in Brecon has flooded after the river Usk flowing under Llanfaes Bridge in the centre of the town burst its banks.

The river has also burst its banks at Crickhowell, flooding the Bridge End Inn which stands on the riverbank.

Yellow and amber weather warnings have been issued by the Met Office across much of mid and south Wales and heavy rain is expected to continue for the rest of the day.

In Brecon two fire crews, one from Brecon and one from Talgarth, are on scene pumping out water from several properties in Watergate where the basements have flooded.

The crews have also cordoned off a short section of the road from the Cat Soup Kitchen to the traffic lights at the bottom of Ship Street and traffic has been diverted through the higher sections of the town.

Traffic is still flowing freely across Llanfaes Bridge but the river has breached the wall alongside the Promenade and completely flooded the path next to the Boar’s Head Hotel.Brecon-based Watch Manager Perkins said four properties in Watergate had had their basements flooded, including the Liberal Democrats office of Brecon and Radnorshire AM Kirsty Williams and Brecon Working Men's Club.He said the road had been cordoned off to give fire crews unfettered access to the flooded properties. He added: "Also you're not allowed to go through there because there's a danger of slates falling off the roofs of these buildings."

Last night Brecon residents received automated phone calls warning them that the river Usk was one of many rivers in Wales likely to burst their banks. The message told residents to consider evacuating their properties if they feared they might be flooded and gave a phone number to call if they actually experience flooding.

Brecon landlord Tyrone Symons said the basement of a property he owns next door to the Liberal Democrats’ office in Watergate was also flooded.

He said the basement had flooded in the past when the river Usk had burst its banks but "thankfully it is rare occurrence".

He said: "When there’s a lot of rain and the river rises it brings the level of the water table up which means we have had flooding in the past. It’s flooded today and the Liberals’ office next door has also been affected. My son’s in the basement now trying to helping the firemen pump out the water. I don’t think anyone is in the Liberals’ office at the moment but the firemen said it’s flooded in their basement too and their pumping that out."Meanwhile Dyfed-Powys Police have urged people not to put themselves at risk, as they deal with the fallout of Storm Callum.Roads across the Dyfed-Powys Police area have flooded putting both the public and emergency responders at risk.People are being asked to stay indoors except for essential travel, such as a medical emergency or to assist a vulnerable person. In particular, people are being urged not to make trips out to see the floods as they may get in to difficulty.A police spokesperson said: "If you do have to travel, read the road and drive carefully – braking distances increase in rain. Never risk driving through flood water."While the demand for police services is high, help them make the most out of their resources and ensure the right calls get through. Consider your options before making contact – in some cases other organisations are better placed to help you."If a tree or power/telephone line is down only call police if there is a significant risk to others or there has been a collision and someone is injured. In such cases call 999. If there is no danger, report it to your local council."