South Wales Police have said that a pre-planned training exercise is being held today.
The exercise involving police and H M Forces at St Athan Airport will test contingency plans and the co-ordination of responses to major incidents.
Police have said: “Local residents or people passing through the area may notice and hear increased noise.
“Risk assessments have been undertaken, and we expect disruption to the public to be kept to an absolute minimum. This exercise has been planned for some time.
“It is not in response to any recent incident, intelligence, or threat. The threat from terrorism remains at substantial, which means an attack is likely.”
The former military airfield at St Athan was transferred to civilian control in 2019 and is now owned by the Welsh Government.
