An eighth person has been charged in relation to the alleged murders of two boys in Melbourne’s outer west earlier this month.

Dau Akueng, 15, and Chol Achiek, 12, were on their way home from a basketball stadium in Cobblebank when they were allegedly set upon by a group of people wearing masks and wielding bladed weapons on Saturday, September 6.

Emergency services were called but both boys died at the scene.

At the time, authorities described the incident as “one of the worst” knife crimes they had seen.

A composite image of two boys, one in a white shirt and one in a collared shirt and dark puffer jacket.

Chol Achiek, 12 and Dau Akueng, 15, were allegedly stabbed to death in Cobblebank in early September. (Supplied)

On Tuesday, Homicide Squad detectives charged a 15-year-old boy with the murder of Dau Akueng.

The latest charge follows another seven murder charges laid in relation to the incident late last week.

A 19-year-old man and three teenage boys, aged 15 and 16, are also facing murder charges over the death of Dau Akueng.

Two men aged 18 and 19 as well as a 16-year-old boy have also been charged with the murder of Chol Achiek. 

Victoria Police said it had increased patrols around the area since the incident and local officers had met with schools, council and community leaders. 

The 15-year-old charged on Tuesday is due to face court at a later date.