Photo: University of Alabama-Hunstville shooting scene.
University spokesman Ray Garner says a woman is in custody but he could not identify her or any of the victims.
Trent Willis, chief of staff for Huntsville Mayor Tommy Battle, says there are several other shooting injuries in addition to the four. He doesn't have an exact number.
Sophomore Erin Johnson tells The Huntsville Times a biology faculty meeting was under way when she heard screams coming from the room.
The shooting happened Friday afternoon in the university's Shelby Center, a science building. University police secured the building and students were cleared from it.
The Huntsville campus has about 7,500 students in northern Alabama, not far from the Tennessee line.