YOKOHAMA (Kyodo) Four workers were seriously burned in a fire Thursday morning at a Tokyo Gas Co. plant in Yokohama, local police said.

The fire broke out shortly before 9 a.m. in Isogo Ward, where the four men were using burners to eliminate moisture around a gas pipe in the basement to prepare it for wrapping with corrosion-prevention sheets, they said.

The workers — two in their 50s and two in their late teens — were taken to a hospital for treatment, the police said.

The police suspect that gas leaked from a cylinder that was supplying gas to the burner and caught fire because a connecting hose was not attached.