US fighter jets have intercepted three small planes in separate incidents this weekend over Camp David, the US presidential retreat, the North American Aerospace Defense Command has said. Two F-15E fighter jets scrambled to intercept a Cessna 182 aircraft on Sunday morning, said the bi-national US and Canadian command, which is responsible for the air defense of North America and responding to unknown or unauthorized air activity. It was forced to depart the area and landed at nearby Carroll County Regional Airport, said officials, without giving additional details or whether the incident in Maryland represented a threat. On Saturday two light aircraft were intercepted and escorted away by military jets in the space of seven hours. Last Saturday, NORAD intercepted without incident a small passenger plane flying near Camp David, where President Barack Obama was relaxing, US military officials said.