More than a dozen people are hurt, including one seriously, after the Stagecoach vehicle overturns into a field off the A385.
A crash in Devon involving a double-decker bus has been declared a major incident by the emergency services.
The vehicle overturned on the A325 near Longcombe Cross, between Totnes and Paignton, at around 11am on Saturday.
Devon and Cornwall Police said one person sustained serious injuries and more than a dozen others have also been hurt.
The Devon and Somerset Fire and Rescue Service say all casualties have been cleared from the scene but the road will remain closed for some time.
Pictures showed the Stagecoach Gold vehicle, which appeared to have been travelling to Plymouth via Totnes, lying on its side.
A witness who saw what happened initially told the DevonLive website: “Very bad accident outside Totnes.
“There are many people with very severe injuries. Maybe 20 with some trapped.
“I was passing and stopped to help but a lot of people too injured to move.”
A spokesman for Stagecoach South West said: “We can confirm one of our buses has been involved in an incident on the A385 between Paignton and Totnes.
“Our immediate thoughts are for those involved and we are helping the emergency services in any way that we can.
“Safety is our absolute priority and we will be assisting the investigation into the circumstances involved in the incident.”
Liberal Democrat MP for Totnes, Sarah Wollaston, said: “Dreadful news, thank you to all our emergency services responding in difficult conditions.”