Mater Lakes Academy in Miami Lakes was placed on lockdown Wednesday after a threat was received, officials said.

Miami-Dade Police responded to the school at 17300 Northwest 87th Avenue to investigate. Footage showed officers carrying rifles at the school.

School officials said they take all threats seriously and said they locked the doors during the investigation, with no one allowed in or out.

Students stayed in class while the threat was investigated. Some students posted on social media that they were told to sit on the floor by teachers.

https://twitter.com/sophialasa/status/776135069585006592

Miami-Dade Police would only confirm that their SWAT officers were in the area of the school.

Dismissal was staggered, with students trickling out of the school Wednesday afternoon. The lockdown was lifted around 4:45 p.m.

Parents received a robo call to alert them about the situation, officials said. Many concerned parents gathered down the street from the school during the investigation.

No other information was immediately known.

Check back with NBC 6 for updates.