A Kalgoorlie-Boulder foster family has been left shaken after their three children and two of their friends were chased by a man driving a ute at high speed while walking home from school.

The primary school-aged children, all Aboriginal and under the care of the Department of Child Protection, were allegedly chased for more than a block by a man driving a Holden ute on Wednesday afternoon.

The incident comes just over a year after Boulder teenager Elijah Doughty was struck and killed by a 56-year-old man pursuing him through nearby bushland.

The foster mother to three of the children, who cannot be identified for legal reasons, said she was shocked when a girl she did not recognise ran into her house for safety.

Walking out the front of her Boulder home, the woman said she witnessed the man pull up and shout abuse at the children.

"We saw a bloke standing at the front … he was already swearing and carrying on to the other girl that had run in there for safety," she said.

"The older girl that he had been abusing — I looked at her and she was just shaking … she was about ready to cry."

She said the man continued to yell abuse at the children, including threats of physical violence, before leaving the scene.

Dispute between kids took nasty turn

While the woman said she was frustrated by an initial police decision not to take her and her children's statement, officers have now begun an investigation.

"Kalgoorlie detectives are investigating a complaint regarding an incident that stemmed from a dispute between several primary school-aged children," a police spokesman said.

"It is believed the dispute was over a scooter [and] a parent of one of the children became involved over the matter."

The foster mother said she was shocked by the man's actions towards the primary school students.

"I would like the police to actually go to his house and explain to him that this is not on ... he should be pulled up about it," the woman said.

"Because he frightened the hell out of these kids; because these kids are aware of what's happened in this town."

'Echoes of Elijah Doughty': mother

While there is no evidence to link the confrontation with any other incident, the foster mother said she felt recent events in Kalgoorlie-Boulder had played a contributory role.

She said the inadequacy of the three-year jail term handed to the man responsible for Elijah Doughty's death by the Supreme Court earlier this year had emboldened would-be vigilantes.

"Now they've got the 'courage' to be able to do that now to any other kids," she said.

"It's only black kids now, you know, their life don't mean stuff all.