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A teenage boy has died and his friend seriously injured in a stabbing outside a school in Sydney's west.
One person has been arrested but it's understood police are chasing a group of up to six suspects.
Emergency services received reports of a stabbing near Doonside Technology High School on Power Street about 3.40pm today.
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Before police arrived, two injured boys drove from the school to Blacktown Police Station, about 15 minutes away.
It was too late for one of the teenagers, who died on the footpath outside the station.
His 19-year-old friend was rushed to Westmead Hospital in a serious condition.
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Police quickly circled the school and homes nearby.
Streets were taped off as officers searched for suspects and possible weapons.
One person was taken into custody.
A red tent remained set up tonight at the crime scene outside the police station where the teenager died.
The police focus was on a group of four to six others on the run, who may be armed.
Anyone with information can contact Crime Stoppers on 1800 333 000.
