At least four police officers were killed on Thursday at Paris Police Headquarters by a colleague who was later shot and killed.

The killer is said to be a veteran police employee in France, worked in computer service for the intelligence division of the Paris Police.

The 45 year old man, moved methodically from his office and slipped a knife through the heavily guarded Police Headquarters in the heart of Paris Killing four of his colleagues before being shot dead in the building’s vast yard compound.

According to Police union official the victims are one woman and three men.

Discontent among police officers was already rising before the attack, and the authorities will almost certainly be asked to explain how a man with a knife was able to enter a heavily secured Police Headquarters filled with armed officers and kill four people before finally being brought down.