A university employee shot dead four fellow staff members in the western Turkish city of Eskisehir on Thursday.
Those killed were the deputy dean, faculty secretary and two lecturers at Osmangazi University, the state-run Anadolu news agency said.
The university's rector, Hasan Gonen, confirmed to CNN-Turk television that four people had been killed.
Police arrested the gunman and were questioning him.
The attacker was a research fellow working in the university's education faculty, the Dogan news agency said. There was no indication of his motive.
Dogan said that the shooting sparked panic at the university, with both students and teachers in a state of shock.
Eskisehir, a city of nearly one million, is on the railway line between Ankara and Istanbul.
Turkey has in recent years been hit by a string of deadly attacks blamed on Kurdish militants and extremists. However there was no indication of any link between Thursday's shooting and extremist activity.
