"Unprovoked attack" means an unexpected or sudden act of aggression or assault without any reason or cause. It describes an attack that happens without any prior provocation or action from the victim. Full definition
Dogs with a history of unprovoked attacks on other animals could also be classified as «potentially dangerous» by the government. (pricebenowitz.com)
Fear of unprovoked attacks from political vigilante group of the ruling government. (ghanapoliticsonline.com)
We have an election to prosecute and win and we are focus... no amount of unprovoked attacks from our founder will shift our focus from the target we have set for ourselves.» (ghanapoliticsonline.com)