A landslip which has caused homes to be evacuated in a former mining town came from a coal tip, the local authority has said.

Dozens of people in Cwmtillery, South Wales, were forced from their homes overnight, as mud and water came up to their windows following Storm Bert.

The Welsh Government has now said that Blaenau Gwent Borough Council confirmed the landslip was a “singular wash-out of a former coal tip in the area”.

The coal tip in the area was category D, which have the “potential to impact public safety” and need to be inspected at least twice a year.

A Welsh Government spokesperson said: “We are fully committed to ensuring our coal tip communities are safe, both now and in the future.

“We are working closely with Blaenau Gwent council and the Coal Authority to provide support to the residents and to ensure that the area is safe.

“The highest risk coal tips (category C and D) are regularly inspected by the Coal Authority and we will continue to work with our statutory partners throughout Wales to inspect and evaluate the highest rates tips in Wales.”

As the mud poured off the hillside overnight, residents in the area were asked to evacuate to an emergency centre.

A berm – a dam made of rubbish – was built across the end of the street to divert water away from the terrace, with a stream still coming down from the top of the hill on Monday morning.

Speaking to the PA news agency, Luc Robertson, a Woodland Terrace resident said: “We just didn’t expect it, we haven’t prepared for it or anything, but obviously we’re just glad that nobody’s injured.

“There was a small (slip) a couple of years ago but it was nothing on this scale.

“All the debris, that’s what’s caused the carnage, it’s going to be a massive clean-up.”

Mr Robertson said he and his partner had been lucky, avoiding the worst of the landslip.

“It took a garage out, I think, at the top (of the hill) the force of the water zooming by, it’s just lucky no one was hurt,” he said.

Rob Scholes, 75, also a Woodland Terrace resident said: “We got moved out last night, the mud came up – it’s already gone down a lot.

“My neighbour phoned and said ‘don’t open your front door’, so I didn’t and we just watched it come up.

Council teams and contractors are on site where we have started initial remedial works to address the immediate issues and work towards a safe return for residents

“I’ve just come back this morning to see the damage.

“To be honest, I really don’t think we’re gonna get this cleared up by Christmas.”

Steve Thomas, leader of Blaenau Gwent council, said: “We can confirm that this occurred on the edge of a Category D former coal tip.

“We are continuing to carry out investigations and are working closely with our partners in Welsh Government and the Coal Authority. We will make a fuller statement in due course.

“Council teams and contractors are on site where we have started initial remedial works to address the immediate issues and work towards a safe return for residents.”