Detectives from Moreland Crime Investigation Unit continue to investigate an incident which occurred in Glenroy on Sunday 21 February.
Highway patrol officers were called to Logan Street, Glenroy about 1.30pm after reports that a number of vehicles were driving dangerously.
When police arrived they observed a number of motorcycles driving dangerously and putting nearby spectators in danger.
When police attempted to intercept the riders a number of spectators converged on police and prevented the officers from carrying out their duties.
A police car was hit and kicked which caused members to disengage to prevent injury to themselves and spectators as well as to prevent further damage to the vehicle.
Investigators have already interviewed five people in relation to the incident but believe more were involved.
Detectives have released images of two men they believe can assist with their investigation.
The first man is perceived to be in his 30s and with short grey hair. He was wearing a white short sleaved shirt with knee length tan coloured pants.
The second man is perceived to be in his 20s and with tanned skin. He was wearing a black cap, black longs sleave hooded jumper with a red stripe across the chest reading ‘Paris’.
Anyone who recognises the men or with further information is urged to contact Crime Stoppers on 1800 333 000 or make a report at www.crimestoppersvic.com.au