Durham – Local police are working with federal authorities to investigate who e-mailed a fake bomb threat to the University of New Hampshire's admissions office Sunday morning after several other schools across the country received bomb threats, too.

The anonymous e-mail was sent at about 4 a.m. Sunday and received yesterday morning around 8:30, UNH Deputy Police Chief Paul Dean said. The message warned of a bomb at Grant House, where admissions is located, and a second bomb in a blue backpack at an "undisclosed location" on campus, but did not make any demands.

An "all clear" was declared at about noon yesterday after a campus-wide search with the help of state police bomb-sniffing dogs and UNH personnel. Grant House was evacuated briefly, but it was business as usual on the rest of the campus for 6,000 to 7,000 students, staff, faculty and visitors, Dean said. Fall classes don't begin until next week.

Dean said several other schools received bomb threats in recent days, including Princeton University in New Jersey, which was e-mailed a bomb threat at about 4:30 Sunday morning. He said Middle Tennessee State University, outside of Nashville, received a threat yesterday and Carnegie Mellon University in Pittsburgh got one last Friday.

It's unclear if the threats are related, but the timing of all of them has police from each campus collaborating with one another and the FBI to be safe, Dean said.

Police are still tracing where the e-mail was sent from, Dean said, and have forwarded the message to the FBI for analysis.

A fake bomb threat was also sent to UNH admissions last April, warning of four pipe bombs on campus. In that case, officials were able to trace the e-mail to a room at freshman dormitory Christensen Hall.

At the time, police questioned two male freshman students, but both were let go and officials said it appeared someone had used a wireless Internet connection based out of their room. The culprits in that hoax were never identified and the case remains under investigation, Dean said yesterday.

Both yesterday's and April's e-mail threats were sent to admissions and in both cases, the culprit used a masking program to try and hide where the e-mail was sent, but Dean said other than that, there are no major similarities between the two messages and it's still unknown whether they are related.

"That could just be that admissions is a focal point of any university and they get a lot of e-mails," he said.

For now, though, Dean said UNH's campus is safe and officials will continue to investigate the bomb threats.

"We feel confident the campus is safe and we'll continue our investigation here wherever it leads us," he said.