Teen stabbed in targeted attack at park filled with parents and children

A teenage boy will undergo emergency surgery, after being viciously attacked at a park in Sydney's southwest.

Witnesses have told police the 16-year-old was allegedly playing soccer at Auburn Park on Hutchinson Street at about 5.30pm yesterday when he was set-upon by a large group.

During the brawl an offender pulled out a large knife, slicing the 16-year-old boy in the neck and arm.

The ugly scenes unfolded just metres away from a playground, in front of parents and children. 

The teenager suffered serious lacerations, and was treated by paramedics, before being rushed to Westmead Hospital.

By the time police officers arrived at the park, the offenders had fled the scene in three separate vehicles - police were told they were a silver Volkswagen Golf, a dark blue Volkswagen GTI and a blue Mazda 3.

9NEWs understands police are treating the incident as a targeted attack, and that it's not a coincidence only one teenager was injured.

The 16-year-old boy will be formally interviewed once he recovers from surgery. 

Anyone with information is urged to contact crime stoppers on 1800 333 000.