Nottinghamshire police have reported that officers and other emergency services are currently attending to an “ongoing serious incident” at various locations.
The Nottingham Express Transit (NET) tram network also said it has suspended all services due to “major police incidents around the city and suburbs”.
Emergency services are present at areas including the Maid Marian Way junction of Upper Parliament Street.
National Inter-Agency Liaison Officers, which co-ordinate the response from police, ambulance and fire services, were also on the scene.
Other roads cordoned off include Ilkeston Road, Milton Street, Maples Street, and Woodborough Road, from the junction with Magdala Road into the city.
A statement from the police said: “There are multiple road closures in place throughout the city while the incident is being investigated.