Three fire engines have been seen on Paris Street and an eyewitness told DevonLive The Mount building had been evacuated.
A cordon was set up around the footpath surrounding the building but it has since been lifted.
It is also understood people have be allowed to return to the building.
The initial cause for the emergency response was unclear.
But Crew Manager James White later confirmed a single piece of paper which had been left on top of a coffee machine had caught fire.
More to follow…