A man with an ax attacked employees inside a tax office in Kozani 2

A man wielding an ax attacked employees at a tax office in Kozani on Thursday, wounding four people.

Authorities said the attack occurred before noon, about 450 kilometres (280 miles) northwest of Athens.

All of the injured were tax office employees, three of whom were hospitalised with serious conditions.

Police immediately responded to the scene and arrested the 45-year-old man.