Police are investigating the death of a horse Monday night in Waialua.

Police said a witness heard dogs barking about 9:20 p.m. and saw several dogs attacking a horse. When officers arrived at the scene, several dogs remained and were picked up by the Hawaiian Humane Society.

Police were trying to determine what killed the horse. Initial reports that the horse had been shot were not confirmed, police said.

Officers opened cases of dangerous dogs and first-degree criminal property damage, which refers to livestock damage worth more than $1,500.

A humane society spokeswoman said the attack happened at Dillingham Ranch.