Security measures will be underway Thursday at Rio Grande City High School after a bullet casing was found on campus.

Rio Grande City High School Principal Maribel Montemayor announced the discovery of the casing on Wednesday evening. 

The discovery comes the day after two students were arrested after posting a threat against the campus on social media.

READ MORE: Starr County teens arrested following threat made against Rio Grande City High School

“As a standard part of our daily procedures and in accordance with our comprehensive campus safety plan, all students undergo thorough security measures each morning,” Montemayor stated in the release. “This includes the use of metal detectors and searches for any potential weapons. We want to reassure the community that, at this time, there is no immediate threat to the safety of our students, faculty, or staff.”

Montemayor added that staff are closely monitoring the situation, and will provide updates as needed.