The factory blaze was brought under control by 40 firefighters

Eight fire crews brought the blaze at Sigma Castings in Grangetown under control.

The firefighter broke his left leg and wrist and the foundry worker suffered cuts to the head when both fell 20ft down a pit, where the fire started.

Their injuries were not life-threatening, said fire officers at the scene.

The fire is believed to have started just after 0900 BST on Wednesday when residual oil caught alight in the pit at the factory, off Penarth Road, near the city centre.

About 10 workers were evacuated, while 40 firefighters from as far away as Tonypandy and Cwmbran brought the blaze under control.

Water from the River Taff was used in the operation

Water was pumped from the adjoining River Taff during the operation, while specialist foam was also used.

The firefighter, who is in his mid-20s, also suffered a suspected broken right wrist and neck injuries, South Wales Fire and Rescue Service said.

Assistant divisional commander Mick Flanagan said five people had been working on maintenance of the foundry building when the fire broke out.

He said: "They were hot cutting nearby and sparks got into the pit and set fire to the oil."