Buildings in Cumbernauld have been evacuated amid fears over a “strong smell” of gas throughout the town.
Students at New College Lanarkshire have been sent home for the day while businesses including a supermarket and the Royal Mail sorting office have been evacuated following the incident at Wardpark Industrial Estate.
SGN said engineers were on the scene to investigate but added they did not believe the cause of the smell was due to a gas leak.
North Lanarkshire Council told STV News pupils from the nearby Greenfaulds High School had not been evacuated from the building.
A spokesperson for the Scottish Fire and Rescue Service said a crew had been dispatched to aid in the investigation.
Residents have been told to keep their windows closed but SGN said they did not believe there was a “safety risk”.
A spokesperson for the firm added: “We’ve received a number of calls regarding a smell in the air, initially in the Cumbernauld area this morning, and subsequently in the Bishopbriggs and Kirkintilloch areas.
“We believe we have located the source of the smell and are working with the third party to resolve the issue on their site. There’s nothing so far to suggest the smell came from our gas network.
“We don’t believe there is a safety risk as there have been no recorded gas readings. We will continue to visit all jobs, but due to the extremely high volume of reports this may take longer than usual.
“However, we would always recommend that anyone who can smell gas should call the National Gas Emergency number on 0800 111 999.”