Westport police are investigating what they say was a "strong-armed robbery" outside a gated condominium complex.Police say the incident occurred at 1400 Post Road East around 9:30 p.m. Thursday. According to police, a resident was trying to retrieve his mail when a Jeep pulled up next to him.Investigators say the person in the Jeep approached the man with a baton-type instrument. The suspect took the man's cash and a watch estimated to be worth $15,000 before fleeing the scene.The Westport Detective Bureau is asking anyone with information on the case to call 203-341-6080.