PARIS (AP) — A French government spokesman says that the man who attacked police officers patrolling in front of Notre Dame Cathedral, crying out "This is for Syria!," was a student working on his doctoral thesis who had not been suspected of radicalization.

Christopher Castaner told RTL radio on Wednesday that police were quickly able to classify the hammer attack as a terrorist act because of "the words he said."

An officer was slightly injured in the Tuesday attack and the attacker remained hospitalized.

No group immediately claimed responsibility, but police searching his residence outside Paris found a declaration of allegiance to the Islamic State group, according to the Paris prosecutor's office.

A student identity card showed he was from Algeria and 40 years old.