Catholic University of America warned students to shelter in place for several hours overnight after a report of a man with a weapon on the campus in the nation's capital, but officials later gave the all clear.

In an email to the campus community early Tuesday, Associate Vice President for Public Safety and Emergency Management Thomasine Johnson said a custodial worker reported being approached Monday night by a man with a weapon who demanded the location of the administration building. D.C. police responded and two buildings were evacuated and searched.

Campus officials warned the campus community to shelter in place during a search and tweeted before 3 a.m. Tuesday that the campus had been deemed safe.

Johnson says no explosive devices were found on campus and the shelter in place order was lifted.