John Bacon

USA TODAY

A lockdown at Southern Adventist University in Collegedale, Tenn., was been lifted and a suspect is in custody, local news media are reporting.

The Chattanooga Times Free Press said the lockdown alarm sounded in Brock Hall on the campus, and the university safety alert said it was not a drill. The paper said word that the incident was over and someone was in custody was sent in a text alert and email 2:25 p.m. to students by campus security.

WRCB-TV reported that an email was sent to students and faculty earlier that read: "This is not a test. We have executed a Campus wide lock down. Campus Safety is investigating a potential threat. Please remain inside and away from windows until a sweep of the campus. Please hold all phone calls. We will send more information as it is available. This is not a test."

The station said Collegedale police were on the campus as well as the campus of nearby Collegedale Academy, and other agencies had been called in. Authorities asked students and faculty to remain hidden until a police sweep could be completed.

Collegedale police told WTVC-TV they had received a "credible off-campus threat" and had immediately locked down the university and other nearby Hamilton County schools. The county schools were later taken off lockdown.

Chattanooga police told WTVC they have taken a "person of interest" into custody at another location. It was not clear if that was the same person mentioned in the text and email announcing that the lockdown was lifted.

Southern Adventist University, owned and operated by the Southern Union Conference of Seventh-day Adventists, has an enrollment of about 3,000 students.