An attack by a 14-year-old who broke into a police station in north-west Bosnia – killing one officer and injuring another – has been described by authorities as an act of terrorism.

The assault happened around at 9pm on Thursday (8pm BST) in the town of Bosanska Krupa.

The assailant, born in 2009, went into the local police station and stabbed the officers in a “totally unprovoked” attack, police said.

Prosecutors working to determine the motive and all the circumstances of the attack characterised it as a terrorist assault. They said the injured officer is in a stable condition in hospital.

Chief Prosecutor Merima Mesanovic said: “Unofficially, the motive is an attack on the institution, ie the police station as an authority, with the aim of intimidating the population.

Police tape outside the station where the attack took place
The incident took place in the town of Bosanska Krupa 120 miles north-west of Bosnia’s capital Sarajevo (AP)

“In addition to the motive, it will be checked whether he was encouraged to do this and whether there are any extreme groups behind him.”

Local police chief Adnan Habibija said the authorities are surprised that a 14-year-old “dared to enter the police station and attack the police officers”.

“I think this is an alarm and we as a society should ask ourselves what is happening here,” he said.

Officials said they could not reveal more details of the attack because the suspect is a minor. Authorities have raised security measures following the attack.

A video from Bosanska Krupa showed a policeman standing in the street with a rifle.

Bosanska Krupa is located some 120 miles north-west of Bosnia’s capital, Sarajevo.