Homicide detectives arrested the men on Friday night and Saturday following investigations into the attack which killed West Australian man Alier Riak, 23.

Mr Riak's older brother, Kuol, 26, was also injured in the brawl in Melbourne's Docklands on Sunday, March 13.

Emergency services responded to the incident at 3.20am, taking the two brothers to hospital where knife-victim Alier died shortly after.

A 19-year-old man from Derrimut and a 21-year-old man from Tarneit have been charged with murder.

A 21-year-old Wollert man, a 22-year-old Taylors Hill man, and a 20-year-old man from Epping have been charged with violent disorder and affray offences.

The Derrimut, Tarneit, Wollert and Taylors Hill men have been remanded in custody, while the Epping man has been bailed to appear at the Melbourne Magistrates Court on Monday.

Victoria Police assistant commissioner Bob Hill said authorities had thrown significant resources at the investigation.

"I know the events of last weekend were incredibly distressing for many in our community," Mr Hill said.

"We experienced the senseless loss of life.

"The victims of this incident were innocent parties who were good people: good students, good athletes and from a good family."

Anyone who witnessed the incident or has information has been asked to come forward and speak to police or contact Crime Stoppers.

1800 RESPECT (1800 737 732)

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Australian Associated Press