A father, his 13-year-old son and their dog have been pulled from a vehicle and beaten by people wielding baseball bats in Palmerston North.
The boy's arm was reportedly fractured, and the son and his father needed hospital treatment. The dog will need veterinary treatment for bruising.
The offenders also "badly damaged" the father's vehicle, say police.
The incident occurred during broad daylight - on Saturday at around 3:15pm, near the intersection of Princess and Main St.
Witnesses told police the attack was "apparently unprovoked", and members of the public rushed to their aid after the offenders had left.
Police say they are "sickened that adult males armed with weapons would attack a young person at any time and are determined to identify the offenders".
The attackers were driving a black Nissan vehicle.
Police are calling on anyone who witnessed the events to call central district police on 06 351 3781. Anonymity will be guaranteed.