(CNN) -- Officials are assuring students of Paine College that it's safe to attend classes Tuesday, after the small Augusta, Georgia, school was rattled by two campus shootings in two days.
The more serious of the two occurred Monday when a student was shot in the head inside an administration building.
The student shot was on the third floor of Haygood Hall and taken to a hospital with life-threatening injuries, school and sheriff's officials said.
Authorities put the college on lockdown for five hours and began a search of dorms.
Two hours later, they had their suspect: a 21-year-old student. Charges against him are pending.
Officials said the suspect and the victim had an altercation earlier.
On Sunday, a student was injured when someone fired into a dorm, Gray Hall. The student was injured by flying debris from the blast through the wall.
The shooter was not a college student, the school said.
Authorities don't think the two incidents are related.
"We're still in embryonic stages of the investigation. And we're still trying to find out all the facts," Richmond County Sheriff's Chief Deputy Patrick Clayton told reporters Monday. "But I would tell the students I think I believe they'll be safe to come to school tomorrow."
Paine College is a private, liberal arts college, with an enrollment of about 900 students.
CNN's Tina Burnside contributed to this report