CHICAGO - An F-15 fighter jet was scrambled on two separate occasions to intercept two single-engine planes that violated a flight ban imposed for President Barack Obama's visit to his hometown of Chicago, officials said. Both small aircraft were intercepted "in the vicinity of Chicago," the first at approximately 10:30 am (1430 GMT) and the second at about 4:45 pm (2045 GMT), North American Aerospace Defense Command said in a statement. Both planes were escorted out of the restricted area without further incident, NORAD said. No details were give about the make of the first aircraft. The second was a Cessna 172.Obama was in Chicago to spend the weekend there with his family and to attend the wedding of the daughter of Valerie Jarrett, one of his senior advisers.