Sydney youth stabbed during fight

A 15-year-old boy is in a serious condition in hospital after being stabbed during a fight in Sydney's southwest.

Ambulance officers were called to a reserve in Yagoona just before 7.30pm on Monday, following reports the teenager had been involved in an altercation with several other youths.

Police arrived shortly after to find him being treated by paramedics for a stab wound to the stomach.

The boy was taken to Liverpool Hospital.