Some 100 tonnes of waste metal were on fire at a scrapyard in Liverpool.
Witnesses reported seeing large plumes of smoke rising from the scene of the blaze in Regent Road, Kirkdale, which started just before 15:35 GMT.
Eight engines from Merseyside Fire and Rescue were sent to deal with the fire. It said it was now under control but crews remained through the night.
No-one is thought to have been hurt and residents are urged to keep windows closed.
Merseyside Police has also been in attendance and there are road closures in place on Regent Road and Derby Road.
The fire service has asked people to avoid the area.