Two people suffered minor injuries in a pre-dawn explosion at a Tata Steel plant in Port Talbot in Wales, the UK’s largest steelworks, police said Friday.

The blast at occurred around 0335 GMT with emergency fire crews rushing to battle the blaze.

South Wales Police confirmed that all workers had been accounted for after an explosion from a train carrying Molton metal into the works caused “small fires”.

“Emergency services remain on the scene but we have had confirmation that all members of staff are accounted for and there are only two casualties with minor injuries,” South Wales Police said in a statement.

“Early indications are that the seat of the explosion was a train which carries Molton metal into the works. The explosion caused some small fires which are all under control and damage to some buildings on the site,” the statement noted.

The police said that the local South West Fire and Rescue Service has confirmed that there is no need for concerns regarding any “hazardous effects” of the smoke from the fire and that the nearby M4 motorway remains open.

Tata Steel confirmed that the fire had been caused by a train carrying molten metal and that an investigation has been launched into the incident.

“We can confirm two of our employees were slightly injured when there was a spillage of liquid iron while it was travelling to the steel plant, according to a company statement on Twitter.

“All fires have now been extinguished. A full investigation has begun,” it adds.

The steel firm said the site had reopened by 0700 GMT and that it was assessing any “potential damage”.

People living in the area near the steelworks reported that their houses shook with the force of a blast at the site in the early hours of Friday.

Sharon Freeguard, a local Port Talbot councillor, said: “I thought I heard about two to three explosions. It was extremely frightening and very, very scary.

“The house just shook, so it was quite alarming. Once it was over, I did wonder what it was and just did think about the works. We’re just all relieved that there are no fatalities.”

Images on social media show large flames at the site and plumes of smoke.

“This incident raises real concerns about safety at the works. It could have been a lot worse. Grateful as always to the emergency services for their rapid and effective response. Tata Steel Europe must conduct a full review, to improve safety,” said local MP, Stephen Kinnock.

India’s multinational steel-manufacturer Tata Steel is one of Europe’s leading steel producers, with steelmaking in the Netherlands and the UK, and manufacturing plants across Europe.

The company supplies high-quality steel products to the most demanding markets, including construction and infrastructure, automotive, packaging and engineering.

Port Talbot produces high-quality steel which is processed at Tata Steels steel mills around the UK for manufacturers in Britain, mainland Europe and other countries around the world.