A teenager accused of being involved in carjacking a Mercedes driver is believed to be influenced by a serious crime gang, a court has heard.

The 16-year-old faced a Children's Court on Wednesday on charges including armed robbery and was bailed with conditions including a curfew.

Police allege he was involved in carjacking a 40-year-old driver in Malvern East early on Tuesday. The driver was repeatedly bumped by another vehicle, then attacked by three offenders armed with a torch.

The court heard the carjacking unfolded after the driver was nudged twice by a white Kia while a BMW drove in convoy. The cars carried six offenders and had stolen plates.

When the victim got out of his car, he was grabbed from behind in a headlock as offenders from the vehicles tried to steal his keys.

He was hit on the head three to four times and struck in the knee, forcing him to hand his keys over.

Constable Rachael Steel told the court the teen saw the assault, but didn't take part. But he gave chase when the driver took photos on his phone of the offenders as he fled.

She also said police believe the teen is heavily influenced by a serious gang, but couldn't say for sure it was Apex, which has been blamed for previous bumping incidents and home invasions where keys were demanded and luxury cars stolen.

Const Steel said the teen had been arrested and exonerated over riots at Moomba in March, which saw men and boys go on a violent rampage through Melbourne's CBD, including those with suspected links to Apex.

Police opposed bail, arguing the teen posed an unacceptable risk to public safety.

But the magistrate said attaching conditions lessened the risk, noting his youth, family support and no prior criminal history.