TALLAHASSEE, Fla. — A gunman opened fire early Thursday at a Florida State University library, sending hundreds of students who had been up all night studying for exams scrambling for cover in the book aisles and barricading themselves in with desks. Three students were wounded before police killed the gunman in a shootout, authorities said.

Police and FSU officials called the shooting an “isolated incident,” but have not released many details, including how far the suspected gunman made it into Strozier Library. FSU’s compact campus is located less than a mile from downtown Tallahassee and the state Capitol.

“This person just for whatever reason produced a handgun and then began shooting students in the library,” FSU Police Chief David Perry said.

The attack started soon after midnight when students inside the multistory library heard about half a dozen gunshots. Students began screaming that someone was shooting at them and flipped over chairs in their race to take cover.

“I ran for my life,” said Allison Kope, a freshman from Cocoa Beach, who was on the library’s first floor. “I ran right out the backdoor. My laptop and everything is still in there. It was shock. It was just instinct. You don’t think about anything else, you just go.”

Other students hid in the book aisles and some barricaded themselves in rooms.

Sarah Evans, a senior from Miami, said she was inside the library and heard a male student say he had been shot. When she looked at him, he was on the ground with blood spreading on his pants leg.

Two of the victims were taken to a local hospital. FSU officials said a third student was only grazed by a bullet and was treated at the scene and released.