MYSTERY surrounds an ‘explosion’-like sound heard by businesses on the Ty Verlon industrial estate on Monday afternoon (January 21).

Staff at several businesses on the industrial estate say they heard an unexplained boom at approximately 1.30pm on Monday (January 21).

Many of them went outside to investigate - but were left perplexed when no-one could work out where it had come from.

Neither the fire service or police have records of anything similar at the time, and there was no incident at nearby chemical plant Dow Corning, where the only loud noise was the usual 3pm alarm test.

James Clode, an office manager at the South Wales Paper Company, heard the noise between 1pm and 2pm.

"It sounded like an explosion," he said.

"It could have been a boom or a bang. It shook the building and we went outside to find out what it was. We walked around the site and realised other people were standing outside their buildings too.

"I have been here for 11 years and I have never heard anything like that before in my life."

He said he initially thought it could have been a similar incident to last year, when a gas cylinder caught fire at the neighbouring ERIKS warehouse, leading to the evacuation of the industrial estate.

But John Morgan, a supervisor at ERIKS, said the noise hadn’t come from them - although staff there had also heard it.

"There was a transporter carrying cars and I thought one of them had fallen off," he said.

"Everyone went outside but you couldn’t see any smoke or anything." Peter Thomas, of PIX Hydraulics on the estate, also heard the noise.

"I was upstairs and you could feel it going through you," he said.

"It was definitely an explosion or something. It wasn’t like a normal bang.

"You could feel the shock wave of the vibration."

"There were people outside but we couldn’t see where it came from."

John Baker, of the nearby KB Facilities Management company, said: “Someone thought it was a tyre bursting on the link road.

"Normally you would be waiting for sirens, but there was nothing."

Meanwhile Richard Mason, of Masons Moving Group, also heard the noise and said it caused quite a commotion.

"I went outside to have a look and everyone from nearby units was out too,” he said.

"It was much louder than a burst tyre. It sounded like something had been hit or dropped from a large height."

He added: "There was a transporter loading cars and the guy behind the wheel stopped and said ‘what was that?’.

"I said ‘I thought one of your cars had fallen off!’ "I have never heard anything like that before in this area."

Another local trader, who didn’t want to be named, said: "It was unusual - I’ve never heard anything like it before. It was an unusually loud bang."

An employee from Lion Laboratories added: "It was loud enough for me to stop working and ask my colleague ‘did you hear that?’ It sounded like it was in the distance."