GWENT cavers said they were “very lucky” to be safe on Saturday after being underground near the epicentre of an earthquake.

The Gwent Caving Club had travelled to Swansea to cave in Ogof Ffynnon Ddu, the second-longest cave in Wales located in the Upper Swansea Valley and had began their excursion before hearing a rumbling.

Jamie Larke, of Blaina, who has been caving for 20 years, said they were climbing an underground waterfall when the rumbling began.

He said: “There was huge rumbling which was ongoing for at least 10 seconds and we thought that there had been a cave-in.

“A few minutes after that there was an awful smell like rotten eggs which usually means there has been some rock movement.

“We had a quick look around in the immediate area and decided everything was OK and carried on with our trip.

“We were totally oblivious to what had really happened.”

Mr Larke, 43, said there was another group in the cave when the earthquake hit, who then told him and the other four Gwent Caving Club members what had actually happened.

“It was quite unbelievable trying to get a grasp on it because it was so close,” said Mr Larke.

“At the time it wasn’t scary really, just shocking. We were about four-and-a-half miles away from the epicentre of the earthquake. It was an ‘explosion’ kind of rumble.”

Mr Larke said the group got out of the cave at about 4.30pm and had lots of messages and missed phone calls from family and friends asking about their safety.

He said: “It only sort of hit then how different the situation could have been.

“We went to the South Wales Caving Club venue, which is about a mile up the road from where we were, and everyone was making sure we were all there and safe.

“We were just glad everyone was OK really.”

The British Geological Survey reported that the 4.4 magnitude quake was centred three kilometres north east of Clydach, near Swansea shortly after 2.30pm on Saturday.

The quake was the biggest event in the area since a 5.2 magnitude earthquake in 1906.