WA teen's death a suspected homicide

The death of a Perth teenager six days after he was found unconscious with head injuries following an 18th birthday party is being treated as a suspected homicide.

Kuol Akut, 17, was found lying on a footpath in Girrawheen just before midnight on Friday and had been in a coma before he died at Royal Perth Hospital on Thursday.

Kuol, who is from South Sudan, was last seen riding along Hainsworth Avenue on a white BMX, which has not been recovered.

Police have interviewed some of the 180 guests who attended the party and are eager to speak to more.

The teenager's family has made a public appeal for information.

In a separate incident about the same time on Friday, an 18-year-old man was found on a nearby footpath with head injuries, but was discharged from hospital the next day.