A TWA jetliner bound for New York returned to Cairo International Airport after taking off Sunday because a telephone caller claimed there was a bomb on board, an airport official said. The official, speaking on condition of anonymity, said the jet returned to the air at 1 p.m. (6 a.m. EDT), 5{ hours later, after the plane was evacuated and its passengers and luggage searched. No bomb was found. He said someone called minutes after the plane took off for Paris en route to New York. The anonymous caller said there was a bomb on the plane and hung up. The official said 156 passengers of various nationalities were aboard the plane. He said one American woman refused to get back on the plane.