An official statement said the four assailants, who shot at police targets in the town before heading to the Crusader-era castle, carried automatic weapons. Large quantities of explosives, weapons and suicide belts were seized in a hideout, the statement said.
It made no mention of their identity or whether they belonged to any militant group, raising speculation they could have been tribal outlaws with a vengeance against the state rather than Islamic State fighters, who control parts of neighboring Syria and Iraq.
A Canadian woman, three other civilians and five police officers were among the nine killed during the exchange of gunfire between the assailants and security forces.
At least 29 people were hospitalized, some with serious injuries.