An investigation is underway after at least two students were wounded in a shooting that took place at a Texas high school on Monday morning, authorities said. 

The shooting at Lamar High School in Arlington, a city located between Dallas and Fort Worth, happened outside of the school building, according to the Arlington Police Department. The department confirmed they arrested the suspected shooter in an update shared to Facebook shortly after the incident.

Two students suffered injuries and were receiving medical treatment, although the nature of their injuries is unknown, CBS Texas reported. 

Police said the school building had been secured once the suspect was in custody and did not believe any active threats to the school remained after the arrest. However, the school was locked down while officers searched and cleared the entire building, the police department said.

“Lamar HS is in lockdown due to an on-campus shooting,” reads an alert notice that the Arlington Independent School District posted on its website Monday. “The shooting occurred outside the school. Please avoid campus while APD investigates.”

Arlington police addressed the families of Lamar High School students still inside the building in their Facebook post.

“Parents, please look out for information from our partners at Arlington ISD regarding student release,” the police department wrote. 

“Lamar High School is currently on lockdown and you will not be allowed on campus,” the message continued. “Although there is no longer any active threat, per our protocols, officers must clear the entire building, which would take some time.”

The department said it will share additional information about the shooting “when we’re able to.”

This is a developing story.