A seven-year-old girl was killed and five other children wounded when a knife-wielding assailant attacked a teacher and students at a primary school in Croatia on Friday, Health Minister Irena Hristic said.

The attack took place at Precko Elementary School in the Precko neighborhood of the capital, Zagreb.

Croatian state broadcaster Hina reported that seven injured people are in hospital, including the five children and two injured teachers.

"The attacker is in police custody and the injured are receiving medical attention," Zagreb police said.

Minister Hristic said the attacker was over 18, while some media reported he was 19.

"We are shocked, as is the entire Croatian public, with the horrible tragedy at the primary school," Prime Minister Andrej Plenkovic said at the start of a government session.

mf/lo (AP, AFP, Reuters)