FLORENCE — Postal inspectors and University of North Alabama police are investigating two threatening items received in the past 10 days at the university’s Math Building, UNA officials said Thursday.

A letter received last week included a written message threatening to kill someone, while the second letter — received Monday — contained a .44-caliber, armor piercing bullet, UNA officials said. The second letter did not include a message. No individual’s name was mentioned as a target of the threat, officials said.

There are 13 faculty members working in the Math Building along with a staff administrative worker, according to UNA spokesman Josh Woods. He said UNA police have discussed the matter with faculty members and increased security measures that include increased patrols. Professors also alerted students about the letters, Woods said.

“Any time a situation like this arises, we take it very seriously while hoping it’s not a threat that is intended to be acted on,” Woods said.

“We will continue to treat the matter seriously until the people involved are found and arrested.”

UNA Police Chief Bob Pastula said investigators have several suspects, and postal inspectors are involved in questioning those people. Pastula did not elaborate on the number of suspects or who they are, but said students, faculty members and community residents are being questioned to determine what, if anything, they know about the letters and suspects.

Investigators, which include agents from the postal inspectors office in Birmingham, are following up on a report that one student appeared to become mentally unstable recently after failing several math classes.

Pastula said the first letter had a Birmingham postmark, which is common for mail sent from the Shoals. Monday’s letter, which contained the bullet, was sent through campus mail.

UNA officials said the address on each envelop was handwritten, which could be useful in the process of finding the person involved.

“We believe the letters came from the same person,” Woods said. “The federal officials and UNA police believe they have some good leads they hope will result in an arrest soon.”

Pastula emphasized the letters were received in the general mail at the Math Building and mentioned no name.

“It is unclear who the threat is intended for, but we are taking this seriously,” he said. “The faculty and students are aware of what’s going on and are asked to notify us if they see anything suspicious or out of the ordinary. Professors have been advised to keep their office doors locked and we have stepped up patrols inside and outside the Math Building.”

Anyone with information about the case or see suspicious activity on campus is asked to call UNA police at 256-765-4357.