CAMBRIDGE, Mass. - Harvard University says an emailed threat sent to hundreds of students and others affiliated with the school may have come from overseas.

The university police department issued a community advisory on Saturday saying that even though its investigation is not complete, it appears "the threat may not be credible."

The email indicated the author would go to the campus on Saturday and target email recipients. Campus police say they are still investigating the threat with the help of other agencies and they're increasing their uniformed and plainclothes presence all weekend.

A campus safety advisory urged people to call police if they see anything suspicious or have safety concerns or pertinent information.

University police advised members of the community to be familiar with Harvard's active shooter protection guidelines.