A gate at a US airbase has been reopened after a security alert this morning.

Security personnel at RAF Mildenhall searched a vehicle at the base's main gate after 'potentially harmful substances' were detected by security staff.

The vehicle was a delivery truck, according to Lt Col James Griffin, 100th mission support group deputy commander.

The truck driver had a pass granting access to base, but was still required to pass through a vehicle inspection.

Base security officials immediately halted all inbound traffic through the base's Main Gate and worked with Ministry of Defence officers to close the A1101 outside the gate for safety purposes.

An spokesman for the 100th Air Refuelling Wing said: 'Following a thorough search of the vehicle, security personnel resolved the incident and restored all traffic to routine operations.

The A1101 has now been reopened.