Two men suffered serious burns following a suspected gas explosion and fire at a house in Tycroes.
Emergency services were summoned to Hafod Road at 4.20pm on Monday, August 4, by residents.
Witness Polly Powell, who called the fire service, described how she heard the explosion and saw flames coming from the property.
“It sounded like a torpedo going off,” she said.
“I immediately called the fire service and moved away from the area in case it happened again.”
Wales Air Ambulance paramedics supported ground crews, who accompanied the injured to hospital.
Another witness said: “I live two streets away, the explosion was so loud and powerful it made my house shake.”
Carmarthenshire County Councillor for Tycroes, Calum Higgins, said: "I've been to Hafod Road to the scene of the incident myself and seen the damage caused.
“It's was obviously a serious incident and residents hope nobody was seriously hurt.
“On behalf of Tycroes residents I would like to thank members of the emergency services, who attended the fire, treated the injured, and made the scene safe."
Wales & West Utilities staff arrived at the scene soon after the explosion.
“Their investigations have found no evidence of any leaks on, or damage to, the gas mains in the area,” said a spokesman.
“Due to the damage to the house, our engineers are yet to gain access to examine the internal gas pipework.
“Our engineers remain on site this morning and we continue to support and work closely with the Health & Safety Executive (HSE) and the Fire Investigation Officer from Mid & West Wales Fire and Rescue Service in their investigations into the cause of this incident.”