A band of intense rain has caused widespread flooding and disruption in many parts of Wales, with more than 20 flood warnings in places across Carmarthenshire, Pembrokeshire and Swansea.

Customers at The Gatehouse pub in Cwmbwrla, Swansea had to flee the rising water at around 15:30 GMT on Tuesday, while there has been widespread transport disruption.

Landlady Vicky Sheffield said she has to evacuate after water started coming up from drains, adding: “In 26 years this has never happened before and now it has happened twice in six weeks. It’s quite scary.”

It comes after the Met Office issued a yellow warning for rain across much of south Wales until 08:00 on Wednesday.

The flooding in Cwmbwrla comes after issues caused by a collapsed culvert first emerged in September.

Swansea council said pumping equipment brought in to alleviate flood waters at Cwmbwrla roundabout has been “overwhelmed”.

It said a blocked sewer – the responsibility of the recently demolished Cwmfelin social club – is to blame.

“We are doing everything we can to reopen the road as soon as possible,” the council said.

National Grid isolated power to 400 properties in around the area for safety reasons, but the electricity has since been restored.

Flooding caused the suspension of rail service between Whitland and Carmarthen and on the line at Pontarddulais.

Jon Davison, the co-owner of the Cresselly Arms in Pontargothi, Carmarthen, is counting the cost after his pub was badly flooded.

“It’s shocking, what can you say? It’s terrible,” he said from his flooded bar next to the River Cothi.

“The bridge piles up with logs every time we have a flood.

“It costs the council a fortune to remove them,” he said, adding things were much worse for people whose houses have flooded.

Wood and debris in the flood water smashed windows, he said, and was at least waist deep in the lower part of the pub.

Pembrokeshire council warned motorists the county is experiencing “widespread surface water flooding”, with many routes closed on Tuesday evening.

Mid and West Wales Fire Service had to rescue several drivers caught on flooded roads, the council added.

Despite the easing of rain in the forecast for Wednesday, the council warned that higher than normal tides could lead to coastal flooding until Thursday.

Farms, properties and roads are also expected to be hit by flooding near the River Towy in Carmarthenshire.

Low lying properties in Ammanford, Llandybie and Aberlash, including Carmarthenshire College, where the river Loughor meets the River Amman, are also expected to be affected.

The Met Office issued a yellow weather warning for much of Wales, from Carmarthen to Chepstow, between 12:00 on Tuesday and 08:00 on Wednesday.

The heavy rain could result in spray and flooding on roads, while bus and train services could be affected, the forecaster said.