(AP) - Police have blocked off several streets near Yale University and put the Ivy League school on lockdown as they investigate a report of a gunman in the area. Yale is advising students and staff to shelter in place. The school in New Haven, Conn., also issued an advisory asking people who are off campus to stay away from the area. There have been no reports of shots fired or anyone injured. The school says on its website that campus, city and state police teams are searching for "any gunman." Television reports show officers in tactical gear outside several campus buildings. A helicopter is hovering over the area. The school is on November break, with undergraduate classes to resume Dec. 2. The school says police received an anonymous call just after 10 a.m. from a phone booth reporting a person on campus with a gun.