Security is being hiked across the county ahead of the start of the NATO Summit on the 4th September in Newport. More than 150 heads of state and ministers including US President Barack Obama will attend the two-day summit. NATO leaders will discuss Afghanistan on the first day and then have a meeting of the NATO-Ukraine Commission before ending the day with a working dinner at Cardiff Castle focusing on security challenges. Friday's discussions include the future of NATO and the transatlantic bond between countries. On 29th August, just days before the start of the Summit, Home Secretary Theresa May announced a change in the official terrorist threat level in the UK to 'Severe'. This threat level indicates that 'an attack is highly likely'. The level is set by the Joint Terrorism Analysis Centre and the Security Service (MI5). NATO warships are present in Cardiff bay and Special Services officers are expected to be present in the area from now through to the end of the Summit. Residents may have noticed increased police presence on the roads in the last few days. Both Severn bridges are possible terrorist targets and security has been increased on these access points to South Wales. These special units are wearing light blue baseball caps to show that the officers are part of the same team, despite 8,000 having been brought in from outside South Wales and Gwent. Around 9,500 police officers are now in the area, sourced from all 43 police forces around the UK. The police must also be ready to deal with demonstrations ahead of and throughout the event. Around 600 protesters demonstrated peacefully on Saturday in Newport and a large 'Peace Camp' has been set up in Tredegar Park. Gwent police issued this statement on 1st September: "As part of the security operation for the 2014 NATO Wales Summit, a number of exercises involving vehicles, aircraft, and officer deployments will take place in South Wales and the South West over the next few days. "Today, 1st September, you can expect to see several helicopters travelling together and landing at the Celtic Manor, Cardiff Castle and other locations in the area. "Please do not be alarmed by these, they are essential to test our procedures alongside our mutual aid policing colleagues and partners from the military. We are grateful for your continued support and we apologise in advance for any disruption these activities may cause." Anyone with information regarding irregular and suspect activity in the area is asked to contact the Anti-Terrorist Hotline on 0800 789 321.