New confronting details have emerged after a 16-year-old bus passenger was stabbed and left for dead on Anzac Day in Joondalup.

On Saturday afternoon, a boy was left seriously injured after being allegedly stabbed by in the chest by another 16-year-old during a violent brawl which had erupted on a bus between a group of teenagers.

The accused teenager from Carramar allegedly used a 15cm filleting knife to stab the boy in the chest, leaving him in a critical condition before both exiting the bus on Grand Boulevard.

The injured boy then collapsed on the path before emergency services were called.

A witness told 7News they used their jumper to hold the wound while waiting for the ambulance to arrive.

“He was seizing and very cold,” they said.

“There was a lot of screaming and chaos happening, and the guy just pulled out a knife and stabbed him in the side.”

It is understood violence had actually started at nearby Joondalup train station between two girls, before the group fight on the bus.

The driver and passengers were left terrified after dozens of the teenagers then began smashing its windows and door, causing $10,000 worth of damage.

Despite the violent behaviour that unfolded yesterday afternoon, the accused boy has been released on bail today, a decision police opposed as they said the teen has a history of carrying knives and would be a concerned to the community.

He has a 24-hour curfew and return to Perth Children’s Court on Wednesday.

The injured boy was rushed to Joondalup Health Campus before being transferred to Royal Perth Hospital, where he is in a stable condition and will remain for a second night.

Police charged a 16-year-old from Carramar with intent to cause grievous bodily harm or prevent arrest wounded or caused grievous bodily harm.

Outside court, the accused boy’s father said his charges were “all b****hit”.