Police are appealing to the public for help in tracking down a missing teen after the death of 16-year-old Pa Sawm Lyhym in Melbourne last week.
The alleged stabbing occurred at Station Place at Sunshine on last Thursday, where it's understood a group of high school students got into an altercation with Lyhym and a group of his friends.
During the incident, the Year 11 Staughton College boy was allegedly stabbed in the neck, while other school students and commuters were around.
Despite paramedics' efforts, Lyhym was pronounced dead at the scene.
Two boys - a 17-year-old from Caroline Springs and an 18-year-old from Burnside - have so far been interviewed by officers, though both have been released without charge.
Officers have now turned their attention to the public for help in locating the third teen involved, 17-year-old Hillside boy Mayik Atem, who they believe can help with their inquiries.
Atem is being described as between 185-190cm tall, with a slim build and black hair in a short dreadlocks style.
He is known to frequent the Sunshine, Hillside, Braybrook and Sydenham areas.
The 17-year-old has not returned home since the alleged stabbing and his family hold concerns for his welfare.
Addressing media this afternoon, Detective Inspector Dean Thomas said retaliation attacks are a "real concern".
"It's certainly a concern to us," Thomas said.
"This act of violence in a public place is a real concern to us.
"We have extra patrols in the area, locally and of course we're doing everything we can to avoid retaliation."
The cause of the fight remains unknown, Thomas said, and a number of weapons - namely knives - have yet to be recovered.
"Images of Atem have been released in the hope someone recognises him and can provide information about his current whereabouts," police earlier said in a statement.
"At this time it is not known if Atem is armed or has access to any weapons."
Two other teenagers were also injured during the altercation and hospitalised, though they are now understood to both be in a stable condition.
CCTV footage taken nearby the scene showed a male in a black hoodie running with a large knife.
Pasawm's older brother, Mawn, 24, told media he was at work when his sister called him to tell him his brother had been stabbed.
Mawn texted his brother and tried to call and Facetime him, but never got through.
A distraught Mawn said he had no idea why his brother, who was the youngest of four siblings and had "never been in trouble", was attacked.
"He was a kind person," he said.
"He was so young."
Anyone with information relating to the incident, or has seen Atem in public, is urged to immediately contact police.
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