Gunfire erupted at the University of North Carolina Charlotte on Tuesday evening, leaving at least two people dead, according to the Mecklenburg Emergency Medical Services Agency. Four others were injured, two of them critically.

Police said one person was taken into custody, though no further details were immediately available on that person’s identity. More than an hour after an emergency alert was sent out to students warning of an “active assailant” on campus, police officers continued to search room by room for students still hiding from the gunman.

NBC Charlotte recorded the suspect being led into Charlotte-Mecklenburg Police Department’s headquarters. Officials reportedly told the outlet the suspect was a former student at the school. Police also said they have no reason to believe another person was involved in the shooting.

Video taken by witnesses on campus showed students fleeing in a panic as police officers first rushed in following reports of shots fired at the school’s Kennedy administrative building. That was followed by an emergency alert from the university urging students to “secure [themselves] immediately” and to “run, hide, fight.”

According to local news station WSOC, the shots were reported around 5:45 p.m. SWAT and ATF were also reportedly on the scene and searching the Kennedy building.

One evacuated student told a WCCB reporter that she and her classmates were sitting listening to presentations when “someone opened a door and started firing.”

“And he kept shooting and I didn’t know what was happening…” she said. “I ducked as soon as I could, and then it just stopped.”