At about noon today Police observed a vehicle of interest on Tirau Road near Karapiro.
The vehicle left the area at speed and headed north.
Police staff undertook a search to locate the vehicle.
The vehicle was eventually found on the Waikato Expressway near Thornton Road where it had come to a stop.
One person of interest remained with the vehicle while a man decamped.
Police, including Armed Offenders Squad members, are currently searching for this person.
Schools, including Cambridge High School, Cambridge Primary School and Cambridge East School, and a number of daycare centres were put into lockdown as a precaution.
Members of the public are requested to contact Police if they note any suspicious behaviour in the area of Thornton Road.
Traffic is currently being diverted northbound from State Highway One onto Tirau Road.
Further updates will be made when available.
Issued by Police Media Centre