Northamptonshire Police leaves bullets on car roof
Northamptonshire Police lost a box of bullets when it was left on the roof of one of their cars while responding to an emergency.
Five bullets are still unaccounted for after the box fell on to a road near Northampton earlier.
Police and dogs have been searching around the A43 roundabout south of the M1 junction 15a, near Northampton.
The case has been referred by the force to the Independent Police Complaints Commission.
Police believe the bullets could have been carried in the tyres of large vehicles.
They have asked the public not to touch anything they suspect to be a bullet and to immediately call 101.
A police spokeswoman said: "Our priority is the safety of members of the public.
"Northamptonshire Police takes the security surrounding armed police and their equipment extremely seriously and this incident will be thoroughly investigated."