For the past few months, police have been logging reports of mysterious discs hovering and weaving over Aliso Viejo and nearby towns. In one sighting, recorded on a UFO research website, a witness reported seeing four craft studded with bright blue lights "dance around one another in the night sky".

　　But now the men behind the UFOs have revealed that they are radio-controlled models and that night flights are not just to shock people but also help sell the craft. Dr Gaylon Murphy, a cardiovascular surgeon from Aliso Viejo, and Steve Zingali, an engineer in Mission Viejo, built the fleet of carbon fibre-reinforced foam flying saucers in their garages.

　　The discs are 3ft in diameter, about 1in thick, weigh less than 17oz and can reach 40mph powered by a tiny electric motor. The flashing lights are fitted around the edge of the disc. "We fly them in formation. It's pretty funny," Dr Murphy told the Los Angeles Times. "People stop, people scream; one cab driver ran his car off the road." The men have already sold four flight-ready saucers for $1,000 (?570) each.

　　Not everyone has found the displays entertaining, however. Erik Strong, the manager of a restaurant in Aliso Viejo, accused the duo of scaring his staff by making the discs hover near the restaurant. "It looked like something right out of a movie, a little too real," said Mr Strong.

　　Local police chief, Lt Richard Paddock, said the men were not breaking the law. "These guys have really done something quite controversial, scary to some people, quite fun in the eyes of most, and who knows where it's going to go," he said.