From the article:
“Hague police said they were hunting a north African man aged between 45 and 50-years-old, with black curly hair, wearing a shawl, a black jacket and grey tracksuit.”
...
“National broadcaster NOS said the attack could not immediately be attributed to terrorism.
NOS, quoting “varied sources”, said: “At this moment there is no indication of a terrorist motive.”
OK
It’s terrorism