A female is in custody after four people were injured in a stabbing on a public transit bus in Brampton Tuesday evening.

The victims were riding the 501 Zum bus eastbound on Queen Street East when the suspect got on at Goreway Drive around 9 p.m., Peel Regional Police say.

An altercation broke out between several riders, investigators say, and the driver stopped the bus some two kilometres away at McVean Drive.

In that time, four people were stabbed, according to Peel police.

Three people were taken to hospital with injuries. There is no update on their conditions. Another victim, a male, was rushed to a trauma centre with serious, but non-life-threatening injuries.

It's unclear what caused the incident, but police don't believe the victims or suspect knew each other.

No charges have been laid.