Highworth Road has been closed after an accident, causing traffic problems.
The road is understood to be closed from the town to the Supermarine roundabout.
Police confirmed they received a call about a two-car accident at 10.45am. But they did not have any information as to whether anyone was injured.
In a Tweet, Stagecoach West warned passengers to expect delays.
It said: “Service 7 currently diverting via Sevenhampton in both directions.Highworth Road is closed between South Marston & Highworth due to an accident. Delays of 15 to 20 minutes are expected. Sorry for any inconvenience.”