Raising new concerns about the vulnerability of movie theaters to attacks by terrorists or deranged individuals, it was reported today (Monday) that as many as 60 persons were forced to flee an AMC theater in Beltsville, MD Sunday night when a large quantity of mace was released during a screening. At least three persons, including a 12-year-old boy, were hospitalized following the attack. Their condition was not disclosed. Television station WTOP reported that police aided fire department personnel with crowd control at the AMC Loews Center Park 8 theater. No arrests have been made, and the incident remains under investigation.