This file video aired Tuesday, Feb. 7 after the school was evacuated. The shelter-in-place order was in effect the following day.

TAMPA, Fla. (WFLA) — Parrish Community High School was under a brief shelter in place order Wednesday after receiving its fifth threat in the past week, the district confirmed.

The school received word of a threat posted on the FortifyFL app, a a school-related app that allows students to report suspicious activity to law enforcement and school officials, and issued the order at 10 a.m.

The district said there was an additional law enforcement presence at the school Wednesday morning. Officers searched the school and gave it the all-clear around 10:30 a.m., then the order was lifted.

There were four other threats at the school in the past week. Two bomb threats prompted an evacuation of the school on Tuesday.

Manatee County Sheriff Rick Wells said the threats don’t appear to be credible, and that his agency is working with the FBI to find the source.

“These threats have come through the FortifyFl app. As you know that’s all about anonymity,” Sheriff Wells said. “The problem we’re having is that when they use the app, the host site may not be in the state of Florida.”

“At one point we believe [the suspect] used a different VPN that you can get online and that IP address was pushed through a host site in Romania,” Wells added. “We’re currently working with the FBI to help us out in Romania and also in California.”