One person remains unaccounted for after an explosion and fire at an industrial estate in South Wales.

A joint police, fire and Health and Safety Executive (HSE) investigation has been launched following the blast at Rizla House on the Treforest Industrial Estate in Severn Road, Rhondda Cynon Taff, at around 7pm on Wednesday.

A major incident was declared by emergency services, with the two-storey building described as “totally alight” and “at risk of collapse” by South Wales Fire and Rescue Service.

South Wales Police said on Thursday afternoon that, while there were no reports of any serious injuries, one person remains unaccounted for.

The fire has since been largely extinguished, the force said, but small pockets remain, with police originally saying they had received “repeat calls” about the blaze starting in the Mindset Gym in Rizla House.

Roads and businesses in the area continue to be affected, but some roads were set to be reopened later on Thursday.

Six pumping appliances, several other appliances and crews remain in attendance, with a high-volume pump used to draw water from the River Taff.

Tim Phipps uses a 2,000 square foot storage unit on the ground floor of the building to operate his business, PG Sound, which rents out audio and visual equipment such as projectors and speakers to the events industry.

The 43-year-old, from Pontypridd, faces an anxious wait to gain access and survey the damage.

“I’m a relatively small business but there’s a fair amount there in terms of value,” he told the PA news agency, adding that he estimates around £100,000 worth of equipment is currently stored in the unit which he has occupied for more than 10 years.

“It’s just the uncertainty and worry, especially just before Christmas.

“People’s whole livelihoods have gone up in smoke, so the future is quite uncertain.

“Everyone is thankful that, as far as we know, there were no lives lost.”

Richard Hayward, 72, who is the landlord of Rizla House, said on Wednesday that there was a “severe explosion” on the ground floor of the 60,000 square foot property, but he did not know which unit the fire started in.

A woman who works at a tattoo studio on the industrial estate said the business has been “destroyed” by the blaze.

Lucy Artiss, 40, a tattoo artist at Sixteen Circles in Rizla House, told PA: “What I know is the explosion destroyed the entrance. Our tattoo shop is destroyed, as well as the gym.

“I left just before it happened so I didn’t witness it,” she said, adding that her co-worker, his client and gym staff “all managed to get out of the fire exit”.

“It was a lovely place, had a wonderful family feel to it. I’m gutted to have lost that.”