TAMPA, Fla. (WFLA) — Students found an empty 9mm cartridge in a parking lot at the University of South Florida Tuesday.

The discovery prompted USF police to conduct a canvass of the area “out of an abundance of caution,” according to a notification sent out later Tuesday.

A K-9 unit from the U.S. Department of Alcohol, Tobacco, Firearms and Explosives assisted in the sweep of Parking Lot 9 on the Tampa campus and the surrounding area.

Authorities said the search did not uncover any additional items or evidence, and that there was no reason to believe there was any active threat to the campus.

However, the incident marked the second unnerving discovery at the campus within the past few days.

This past Saturday, someone in the USF Fine Arts Building found an empty gun magazine and a gun case in a bathroom. A search was carried out, and police said there was no threat.

There had already been heightened security concerns following a deadly mass shooting last week on the Florida State University campus.

A few students shared their unease with News Channel 8 after Saturday’s discovery, with some choosing not to show up to class Monday.

“That underlying anxiety is there,” one USF student said.

Since the April 17 mass shooting, the USF Police Department said there’s been increased law enforcement visibility on campus. Students are also asked to report anything suspicious.

“USFPD remains committed to ensuring the safety and well-being of all students, faculty, staff and visitors,” the notification sent out Tuesday read.