A coach carrying 32 tourists overturned this afternoon at around 2.10pm.
According to a spokesman for Police Scotland, five people are thought to be seriously injured, but their injuries are not life threatening.
A further 25 people were described as 'walking wounded'.
The road is expected to remain closed 'for some time'.
The spokesman said: "Around 2.10pm hours this afternoon, Thursday 26 March, a coach with tourists, overturned on the A83 Rest and Be Thankful. "It is understood that 32 people on board of which five are believed to be seriously injured (but not thought life threatening).
"They are being taken by ambulance/medivac to either the Southern or the RAH for treatment.
"Twenty five people are described as 'walking wounded'."
A spokeswoman for BEAR Scotland said it would be likely the road would remain closed for some time.
She said: "The road at the A83 Rest and Be Thankful is currently closed due to a serious road traffic accident involving a coach. "BEAR Scotland is currently assisting emergency teams at the site.
"A further update will be issued early evening however the road is likely to be closed for some time Emergency Services are at the scene."
A diversion route is being put in place via A82 Tarbet, A85 Crianlarich, A819 Dalmally and A83 Inverarry.
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