MEHLVILLE, Mo. – Police and school officials are investigating a threat Friday morning at Mehlville High School in south St. Louis County.

The St. Louis County Police Department is investigating that source of the threat, which is not believed to be credible. The Mehlville School District says the threat was made anonymously, but not disclose further details on circumstances around the threat.

“All students and staff are safe. We will have increased police presence and increased supervision at Mehlville High School throughout the day today,” says the district in a statement to FOX 2.

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On Wednesday, two days after a deadly school shooting after Central Visual and Performing Arts High School, the FBI increase in “hoax threats” made toward St. Louis area schools. Many schools have increased their law enforcement presence throughout the week.

Since Monday, police have also investigated threats at Belleville East High School and O’Fallon Township High School in the Metro East and in the Hazelwood School District in St. Louis County.

This is the message school administrators sent to parents:

Mehlville High School families and staff,

In partnership with St. Louis County Police, district administration has identified the source of the threat and determined it was not credible. The building is safe.

Thank you to the students who immediately reported the threat when they received it this morning. We’d also like to thank St. Louis County Police department for their continued support and assistance.

This continues a pattern of anonymous threats that quickly spread among our student community. These anonymous threats are disruptive to student learning and divert both district and police resources away from necessary functions.

Those involved in making threats against school safety will be held accountable for their actions in accordance with our discipline policies.

We encourage students, staff and parents to report any safety concerns they have to their school principal or if it’s after hours, to safety reporting hotlines. If threats are made via social media, please do not continue to share the threats via social media. This makes it more difficult for police to investigate and identify the original source. Please report threats made on social media via the social media reporting mechanism.

Thank you for your patience, understanding and partnership as we work to provide our students with a safe learning environment.

Chris Gaines, Ed.D.

Mehlville High School