TEHRAN (Agencies) - Iranian security forces foiled a hijack attempt on Saturday, arresting a man who said he had planted a bomb on a flight from Tehran to Damascus, the semi-official Fars news agency reported. The suspect was arrested by the security forces inside the plane, Fars said. There was no bomb, and the plane later landed safely in the Syrian capital, it said. Iranian air marshals have arrested a 'mentally unstable man who threatened to hijack a Syria-bound Iran Air passenger plane, an airline spokesman told Mehr news agency.