Harvard University alerted due to explosives threat

At least four (4) buildings in Harvard University were evacuated after a report of presence of explosives came out on Monday morning.
In its website, the university published an alert telling people to vacate the place:

..unconfirmed reports of explosives at four sites on campus: Science Center, Thayer, Sever, and Emerson. Please evacuate those buildings now.

The report is now being investigated by the university and Cambridge police.

The 210 acres Cambridge campus (main) of Harvard University is regarded as the most famous among others. Its student body is around "6,700 undergraduates and another 14,500 graduate and professional students".