A riot van and several police cars have been called to an incident on the Embankment - understood to have taken place on board a bus.
Several motorists spotted the commotion, near the Esso petrol station on Plymouth Road, at lunchtime on Sunday.
Eyewitnesses said up to seven police units were at the scene, including a riot van, at around 1pm.
Nobody from Devon and Cornwall Police has been available for comment and it is unclear if any arrests have been made.
Staff at the neighbouring...
