The incident has been ongoing by East Surrey Hospital in Redhill since around 11.30am today (February 26).
The main hospital entrance via Three Arches Road from Horley Road is blocked with a diversion set up for vehicles and pedestrians.
Emergency access to the hospital is still possible by the diversion in place.
A Surrey Police spokesperson said: “We are dealing with a concern for safety near to East Surrey Hospital in Redhill.
“The main entrance road from Horley Road towards Three Arches Road is currently out of use and pedestrians and road users are being redirected.
“Please avoid the area if you can at this time. Those requiring emergency access to the hospital are still able to do so via the diversion in place.”
Surrey Police have been contacted for further details of the incident.
