A lockdown at the Robstown Early College High School sparked plenty of concern Tuesday from Coastal Bend residents.

The school was placed on lockdown around noon after police said an altercation between a male and female student led to threats of violence. The threats were reported to authorities and an investigation began.

"We got the call earlier today. Both lieutenants were here. Patrol was here. As you saw, other agencies responded with us as well," Robstown Police Chief Erasmo Flores said. "The school was in lockdown and we took action as soon as possible."

Additional units from the Robstown Police Department and Department of Public Safety were called in to assist in the investigation. No students were hurt, and investigators found no credible threat.

The lockdown lasted about an hour, and parents at the school were visibly shaken.

"She was apparently sitting in the dark in the classroom. She said, 'Mom, they said it was Code Blue but we don't know what the heck is going on,'" said Nicole Flores-Martinez, a parent who was communicating with her child during the lockdown. "And they said its a Code Red, and then we see all of these cops and we see them with guns and bulletproof vests, so we're, of course, all of these parents are freaking out not knowing what's going on."

Police said they have two officers stay at the school from 7:30 a.m.-4 p.m., and the same goes for the middle school.

As for repercussions to the students involved, Chief Flores said that is up to the school district.

Stay connected with 3News for the latest news, sports, and weather. Download the KIII-TV 3News app now.

Have an idea for a story? Send news tips to news@kiiitv.com, and visit us on Facebook, Twitter, and Instagram!