Armed cops have swooped on the production site of open air show Kynren as part of a terrorism exercise.
The event, held today, was designed to test the skills and processes of police, other emergency services and the local authority.
Durham Constabulary has said it is keen to stress the exercise was not in response to any specific threat to the region or to the site where this event was held.
It was, however, a chance for police and partners to test exactly how they may respond in difficult circumstances.
Chief Insp Graham Milne, from Cleveland and Durham Specialist Operations Unit, said: “This is one of a number of routine exercises organised to test the response of the emergency services and other partner agencies. It is in no way linked to a specific threat.
“We carry out exercises to test contingency plans and the co-ordination of the response to a major incident on a regular basis.
“The national terror threat remains at 'Severe' and recent events in this country and across Europe show that we need to ensure we are prepared in the event that something does happen in our region.
“It is important that we continue to test our emergency response procedures to ensure the safety of our local communities.
"A huge amount of work and preparation was put into this exercise and I want to thank everyone at Kynren in particular for their support.”
Involved in the exercise were Durham Constabulary, County Durham and Darlington Fire and Rescue Service, the North East Ambulance Service, Durham County Council, and Kynren organisers.
Dominic Brown, Area Manager for Emergency Response at County Durham and Darlington Fire and Rescue, said: “Being part of this exercise has presented us with a great opportunity to work closely with our emergency services partners and other agencies to test our response to an incident of this nature should the worst happen.
“This is all part of being prepared to keep the people of County Durham and Darlington as safe as possible.”
NEAS HART and Resilience Manager, Marianne Walton, said: “This was an excellent opportunity for NEAS to work alongside our colleagues from Durham Police and County Durham and Darlington Fire and Rescue Service and the local authority.
“We were able to test our plans to respond to an incident of this type where we would have to deal with a large amount of injured casualties.”
Roger Goodes, Head of Communications and Information Management at County Durham Council, said: “We routinely work with our fellow emergency responders on a broad range of themed exercises to ensure we can react quickly and effectively to whatever the situation may be.
“Every exercise brings fresh challenges that help us look collectively at resolving whatever the scenario is while making sure that we have plans in place to work together effectively and are able communicate clearly with the public.”
Anne-Isabelle Daulon, Executive Producer of Kynren, said: “Kynren is first and foremost a community endeavour and as such, we are delighted to show our support to the superlative organisations that are our emergency services by lending our infrastructure for their training exercises.”