Authorities have warned others in the area to use caution and said the animals involved would be exterminated if possible.
A four-year-old girl was bitten on the leg by a dingo at Dales Campground, in Karijini National Park, on Wednesday night, authorities said.
The girl's mother was also bitten while attempting to protect her, with both receiving first aid onsite before being transported to Tom Price Hospital for treatment.
Earlier in the week, about 8am on Saturday, a six-year-old girl was approached by an aggressive dingo that nipped at her clothing. She was not injured.
On Monday, a six-year-old boy was bitten on the neck and arm and was taken to Tom Price Hospital by his parents for medical treatment.
Rangers have been conducting nightly patrols since the initial attack to locate and humanely destroy the problem dingoes as soon as a safe opportunity presents, WA's Department of Biodiversity, Conservation and Attractions said.
Additional staff with specialist dingo management experience have also flown up from Perth to assist.
The campground remains open, with park rangers advising campers of the dingo risk on arrival and providing safety information.
"The Parks and Wildlife Service is urging anyone travelling to Dales Campground at Karijini National Park to be on the alert and take every precaution," the department said.
"There is permanent dingo safety signage installed at several locations within Dales Campground."
The department said dingoes were an important part of the local ecosystem, but visitor safety was the number one priority.
14°C