Three of the people accused of murdering Perth teenager Cassius Turvey are alleged to have kidnapped and assaulted another boy days earlier.

Cassius, a 15-year-old Noongar Yamatji boy, was allegedly chased and bashed with a metal pole as he walked home from school with friends on October 13. He suffered serious head injuries and died in hospital 10 days later.

Four people have since been charged with his murder. They are yet to enter pleas.

Police on Wednesday said three of the accused were facing fresh charges relating to a separate attack on another 15-year-old boy.

The boy was allegedly chased through the Swan View area on October 9 before being caught and punched, kicked and stabbed.

“It will be further alleged the boy was placed into a vehicle and taken to a house where he was detained for a period of time before being released,” WA Police said in a statement.

Jack Steven James Brearley, 21, Mitchell Colin Forth, 24, and Aleesha Louise Gilmore, 20, will face court on later dates in relation to the incident.

All three have been charged with detaining another with intent to compel the doing of an act.

Brearley and Forth are also charged with aggravated unlawful wounding.

An 18-year-old Bellevue man is facing both charges and was refused bail to face Midland Magistrates Court on Wednesday.

He has not been charged in relation to Cassius’s death.