This is a breaking news story. Check back for updates.
UPDATE 12:17 p.m. EST: While media reports suggest that the bomb threat was a hoax, Harvard still hasn't confirmed those reports.
"Report of bombs on campus remains unconfirmed," the school posted to its website at 11:48 a.m. EST.
UPDATE 11:33 a.m. EST: According to the New York Daily News, officials have determined that the bomb threat was a hoax. The paper added that the threat was sent in an email.
UPDATE 11:05 a.m. EST: As of 11 a.m. EST, no explosives have been found, Harvard University Police Department spokesman Steven Catalono told the Harvard Crimson.
UPDATE 10:46 a.m. EST: Harvard Yard is closed to everyone except residents with a Harvard ID, the school said in the latest update posted to its website. The university's police department and the Cambridge Police Department are investigating the unconfirmed reports of explosives on the Harvard campus.
"Harvard's focus is on the safety of our students, faculty and staff. We will continue to update the community via MessageME and through messages posted here and on the University's Twitter and Facebook accounts," the university said.
UPDATE 9:53 a.m. EST: The Harvard Crimson reports that final exams scheduled for Monday morning have been canceled.
UPDATE 9:40 a.m. EST: Harvard said on its Twitter account that there have been no reports of explosions.
Unconfirmed reports of explosives at four sites of the Harvard University campus prompted the school to order evacuations on Monday morning.
Harvard’s Science Center as well as Thayer, Sever and Emerson halls are the sites where the university is issuing the evacuations.
“Please evacuate those buildings now,” Harvard posted on its website.