Five people are in custody after the fatal stabbing of a teenager in a brawl in Sydney's west.
Police found four people with stab wounds after being called to the intersection of Suffolk and William streets in Blacktown about 10pm on Wednesday.
An 18-year-old man died at the scene despite the efforts of paramedics.
Two 15-year-old boys were taken to Westmead Hospital - one in critical condition, while the other is in a serious condition.
A 21-year-old man and four teenagers - a 14-year-old and three 17-year-olds - were arrested by officers, with assistance from PolAir.
The man and one of the 17-year-old boys were taken to Blacktown Police Station.
The second 17-year-old boy was taken to Riverstone Police Station.
The third 17-year-old boy was taken to Blacktown Hospital and the 14-year-old boy was taken to Westmead Hospital. Both remain under police guard.
A further three teens - a 19-year-old man and two aged 18 - were taken to Mt Druitt Police Station and interview before being released pending further inquiries.
Blacktown is one of 12 COVID-19 hotspot local government areas where the virus is surging and the state's toughest restrictions apply.
This includes a 9pm-5am curfew, except for authorised workers and emergencies.