UP to 600 tonnes of landfill material on fire in Newport is expected to burn overnight, according to reports.

Fire crews have been battling the blaze at Able Skps since around 2.10pm this afternoon.

But as time has gone on, South Wales Fire and Rescue Service has reported more and more of the building on Nash Mead has been affected.

Around 85 per cent of the 50m by 20m space is said to be on fire and replacement crews are currently being drafted in, a spokeswoman for the fire service said.

Twenty three firefighters are tackling the job.

"It's going to be a protracted incident into tomorrow. The advice to residents is to keep windows and doors shut," the spokeswoman added.

Originally, the fire was said to have been in a skip outside the building.

However by 4.15pm, crews requested an extra engine should attend, as the flames had spread to 75 per cent of it.

Three fire engines, a water bowser and a hydraulic platform are at the scene.

The spokeswoman said there appears to be no risk to nearby buildings.

The cause of the blaze is not yet known.