Five buildings at RMIT's city campus have been reopened five hours after students and staff were evacuated due to a threatening email.

Buildings 11, 13, 55, 56 and 57 were mentioned in an email to the university, which threatened violence.

RMIT buildings have been evacuated. Credit:Courtesy of Seven News

Chief Operating Officer​ Dionne Higgins said the buildings were temporarily closed as a precaution.

It is understood security sweeps were carried out.