Monmouth University deemed safe after lockdown on New Jersey campus. What to know about classes Tuesday.

WEST LONG BRANCH, N.J. -- Monmouth University's main campus was on lockdown overnight in New Jersey, but investigators say it has now been deemed safe. 

Students and staff were advised to shelter in place for several hours on the university's main campus in West Long Branch.

School officials say the campus will have a delayed opening at 10 a.m. Tuesday, with classes starting after 11 a.m.

Monmouth University on lockdown overnight

The Monmouth County prosecutor's office said police were called to investigate a threatening email from someone who claimed to be armed on campus. 

"Shortly after midnight on Tuesday, July 23, the Monmouth University Police Department received reports indicating that students and faculty had received an email from an individual alleging that they were armed and hiding on campus, where a dangerous device had also been placed," the prosecutor's office said in a press release.

Prosecutors said police searched the campus and gave the all-clear around 8:30 a.m.

"A search of University buildings was conducted, and the preliminary investigation has revealed no indication of validity to either claim outlined in the email sent to students and faculty. An all-clear alert was issued to the campus shortly after 8:30 a.m., and law enforcement then cleared the scene," the release continued. 

Monmouth University main campus has delayed opening

The university posted the latest update on its website shortly after 7:15 a.m., which read:

"Monmouth University is continuing its investigation. Campus will have a delayed opening at 10 AM and classes will start after 11 AM. As we continue our investigation, residents are still asked to shelter in place. As any information becomes available, we will update you immediately."

So far, no charges have been announced.