LONDON - Britain's Gatwick Airport evacuated its North Terminal as a precautionary measure due to an incident, the London airport's twitter feed said on Saturday.The evacuation came amid heightened security after attacks in Paris left more than 120 people dead on Friday and Britain's Prime Minister David Cameron convened a meeting of his government's emergency response committee. Britain's terrorism threat level stands at "severe", the second highest category which means a militant attack is considered highly likely.Gatwick airport is the country's second busiest airport and is situated about 30 miles south of London. Prime Minister David Cameron there would be no change to Britain's terrorism threat level in light of the attacks. The level has since August 2014 stood at "severe," the second-highest category."The threat is already at 'severe' which means an attack is highly likely and will remain so," he said in a televised address on Saturday, adding some of the casualties were likely to have been British.