Two workers have been injured after a natural gas leak and flash fire at a pipeline compressor station in northern B.C., the Transportation Safety Board confirms.

Spectra Energy, which owns and runs the pipeline and station northwest of Fort St. John, said Wednesday that the incident occurred on Saturday.

One of the injured workers has been released from care in Fort St. John, while the other has been transferred to Vancouver General Hospital for further treatment, according to the BC Ambulance Service.

"The facility was undergoing what we term "turn-around activity," which is annual maintenance of the [compressor station]," said Spectra Energy spokeswoman Rosemary Silva.

In a written statement, the TSB said one of their investigators has been dispatched to the scene of the incident, approximately 160 kilometres north of Fort St. John, and is expected to arrive Thursday.

With files from the CBC's Wil Fundal