A woman is in custody after three people were seriously injured in a Brampton stabbing on Saturday morning, Peel police say.

The stabbing happened inside a residential unit above a store at Main and Queen streets. Emergency crews were called to the scene at about 10:50 a.m.

When officers arrived, they found the woman and two men suffering from stab wounds.

Peel paramedics took the woman to a trauma centre in life-threatening condition but her condition has been upgraded to non-life-threatening.

Paramedics took one of the men to a trauma centre but in serious and not life-threatening condition and the other man to a local hospital in serious condition.

Police said the female suspect, 34, has not yet been charged.

The stabbing was "targeted and isolated," according to Const. Akhil Mooken, spokesperson for Peel Regional Police.

"This was not a random attack," he told reporters near the scene.

Mooken added that the suspect and victims knew each other, but he declined to comment on the nature of the relationship.

Police are maintaining a presence at the building as officers continue to investigate, he said.