Hundreds of workers have been evacuated from Leeds City Centre and roads are closed off after a suspicious package was found.
The army have also been called to the scene near Wellington Street and York Place following a call from a member of the public.
Matt Naylor, 46, works at HTC Architects on the corner of Britannia Street and York Place near the scene.
His building is right on the boundary of the cordon, although his office has not been evacuated.
West Yorkshire Police said:
Connor Hart, who works in one of the offices nearby, said:
Police are going door to door and asking people to leave.
An officer at the cordon is telling people that it could be several hours before they are allowed to return.
Officers have also cordoned off King Street and traffic is being diverted.