No-one was reported hurt in the fire at the Shotton site

The last of the firefighters left the scene at around 0452 GMT on Friday morning. No one was reported hurt.

The fire was first reported at lunchtime on Thursday in the former electrogalvanising area of the site.

The fire service said there was a blast at 1545 GMT. Some residents near the plant were advised to keep windows and doors shut.

The cause of the blaze is still unknown. Twenty workers on a neighbouring line were moved from the area, and will return once the area is deemed to be safe.

There was no damage but a substantial amount of clean-up work will be necessary which are we are getting on with Corus

The rest of the site has continued to operate normally.

A spokesman for Corus said damage appeared to be contained to a fairly small area with no major damage to walls and the roof.

A spokesman said: "Our engineers have inspected the production line which was evacuated yesterday, there was no damage but a substantial amount of clean-up work will be necessary which are we are getting on with.

"The production line was on a scheduled maintenance period which will be restarted as planned later in December."

Thermal imaging camera

On Thursday, police told residents living east of the plant, in Garden City, Sealand and the Queensferry area, that the smoke from the fire was not toxic.

The fire service deployed nine fire tenders, from Deeside, Holywell, Buckley, and Chester as well as an aerial platform from Wrexham and a foam carrier from Deeside.

Relief crews were brought in to help with the incident. More than 50 firefighters were at the scene nine hours after the blaze broke out.

A thermal imaging camera was used and a lighting generator was at the scene to help the firefighters.

The alert comes three years after three men were killed in the Corus steelworks in Port Talbot, south Wales, in a blast in the site's furnace number five.

The inquest into the deaths of Andrew Hutin, Stephen Galsworthy and Len Radford had been due to be held in September but has been postponed until the new year.