The family of a teenager wanted over a fatal stabbing fear for his safety as police attempt to stave off retaliation attacks.
A search is under way for the Hillside youth after 16-year-old Pa Sawm Lyhym was fatally stabbed at the Sunshine bus station in Melbourne's west on Thursday.
Police are pleading for the 17-year-old to turn himself in, alleging he's a "significant player" in the incident and urging the public not to approach him and instead call triple zero.
Officers do not know if he is armed.
"People need to be aware that if you are harbouring or assisting (him) to avoid speaking to police, then they may find themselves subject to accessory to this murder," Victoria Police homicide squad Detective Inspector Dean Thomas said on Tuesday.
Police allege a fight between two groups of teenagers on Thursday afternoon led to the 16-year-old's death, with another boy hospitalised and a third treated at the scene for injuries.
A 17-year-old Caroline Springs youth and an 18-year-old Burnside man were previously interviewed by police before being released from custody, but Det Insp Thomas stressed the duo remained subject to investigation.
Investigators are yet to determine the motivation behind the fatal stabbing, but have said the two groups were involved in "tit-for-tat" incidents in the lead-up to the fight.
Police harbour fears for potential retaliation attacks.
Officers are conducting "reassurance patrols" in relevant areas, with the teenagers involved understood to attend schools in Melbourne's west.
The 17-year-old Hillside youth was last home on Friday and his family was co-operating with officers.
Det Insp Thomas acknowledged it was a possibility someone else could get to him before police.
"His family are concerned about that also, that whilst he does remain in the community ... there is a risk to his own safety," he said.
"We're concerned whether he gets involved in further acts of violence."
Det Insp Thomas urged families to take responsibility for their children and said police were working with the community to combat the violence.
"The majority of young people don't carry knives, but unfortunately we see the ones that do," he said.
Police described the 17-year-old as between 185 and 190 centimetres tall, with a slim build and short black hair in a dreadlocks style.
