It took fire crews several hours to get the fire completely under control

Thirty six workers at the Trostre plant near Llanelli needed medical treatment after Wednesday's blaze on a production line.

Twenty three staff were taken to hospital as a precautionary measure and a further 13 treated on site.

An investigation into the cause of the fire is being carried out.

The plant, which has a workforce of around 1,000, was evacuated when the fire broke out on one of four production lines on which strip steel is coated with tin to make cans.

All the people working on the line will be found other things to do in the meantime and no jobs will be lost. Corus spokesman Mike Hitchcock

All those taken to hospital have been released and the majority of them are back at work on Thursday.

However, production at the plant which produce tinplate 24 hours a day, seven days a week has been hit. The line where the fire occurred is still out of operation.

"Engineers at the plant will today assess the damage to the line and see what needs to be done to get it working again," said Corus spokesman Mike Hitchcock.

"At the moment we don't know when it will be operational.

"All the people working on the line will be found other things to do in the meantime and no jobs will be lost.

"It will have a minimum impact on our customers as we have stock and the product is also made on two lines in Holland" added Mr Hitchcock.

The fire broke out around 0900 BST on Thursday and was brought under control by 1600 BST.

Mid and West Wales Fire Service said no-one was trapped inside the plant and that no chemicals were involved in the blaze.

Police reassured residents that thick black smoke coming from the fire was not toxic and no chemicals were involved.

Local resident Glen Graydon said he was at a car wash near the Trostre works when he saw an emergency vehicle going past with flashing lights.

"There was an acrid smell, and after a while I noticed black, acrid smoke coming out of the big chimney stack," Mr Graydon said.