Roads have been closed and between 15 and 20 homes evacuated following a large gas leak in Maidstone.
Kent Police said the public should stay away from the area of South Park Road following the gas leak, which was reported at 15:38 GMT.
An evacuation centre has been set up at nearby Maidstone Leisure Centre in Mote Avenue where facilities are being laid on for residents.
South Park Road, Mote Road, Parkway, West Park Road and York Road are shut.
A police spokesman said police, Kent Fire and Rescue Service and gas engineers were at the scene and working to get people back into their homes.
He was not able to say when they would be able to return.
Police said the odour in the area, similar to rotten eggs, was caused by a chemical added to odourless natural gas. It was not toxic and posed no risk to public health.
People able to be at home were advised to stay indoors and keep windows and doors closed.
Kent Highways said emergency services were dealing with a "large gas leak".