Three employees were shot dead on Wednesday at a school in the town of Sanski Most in northwestern Bosnia and Herzegovina by a co-worker who then tried to kill himself, police said.

Police were notified at 10.15 a.m. (0815 GMT) that a man had opened fire at the school with an automatic rifle, spokesman for the local police Adnan Beganovic said.

The shooter killed the school's dean, the secretary, and a teacher, he said. "He tried to commit suicide and was gravely injured," Beganovic said.

The school had not yet reopened after summer holidays, so no children were involved and an investigation into the shooting is underway.

(With input from Reuters)