"We're investigating a terrorist murder"

Federal prosecutors are treating the case as a terrorist murder and are investigating whether anybody else was involved. Prosecutors stressed that all avenues were being investigated including a link with IS. They noted that a quick intervention by Liège police had averted a bloodbath.

At one point the killer strolled in and out of a café as if he was looking for fresh victims but because the landlord had told everybody to flee tragedy was averted.

One day after repeat offender Benjamin Herman shot two women police officers and a young student dead in Liège many questions still surround the motives for these crimes.

The investigation into the killings and a fourth earlier in the week is in full progress. A search of Herman's jail cell at Marche-en-Famenne prison yielded no results. Investigators are examining whether Herman's slaying of two women police officers was motivated by a hatred of the Belgian police and by extension the Belgian state. The head of Liège police yesterday spoke of Herman consciously targeting police officers.

The method used in the killings betrays determination. He attacked from the rear with a knife and then shot the officers dead with their police gun. This method has been compared those portrayed in IS propaganda.

Herman was involved with drugs in the past. The post mortem will have to establish whether the killer was high on drugs on Monday.

Belgian home minister Jambon: "Possibly he was radicalised (in jail). It's possible he saw no prospect of a future following Monday night's killing. Herman may have been high on drugs. Many questions remain."

Mr Jambon thinks it's likely that Herman was responsible for a fourth killing, the murder of a man who shared Herman's jail cell, earlier in the week.