Madrid (CNN) A man was shot dead early Monday morning after entering a Spanish police station wielding a knife, Spanish police told CNN.

The incident, which took place in Cornella, just outside the northeastern city of Barcelona in Catalonia, is being treated as a "terror attack," according to regional head of criminal investigations Rafel Comas.

He added that "it was a clear act of aggression against a police officer inside a police station" and "the individual uttered references to Allah" during the incident.

Police are still working to confirm the identity of the attacker.

Comas added that the attacker "was not known to be affiliated with any jihadist cell."