Boy critical after Sydney house party

A 16-year-old boy has been arrested after two other boys were badly hurt in an alleged fight at a Sydney house party.

Police were called to a house in Five Dock on Friday evening following reports of a backyard fight.

Officers found a 17-year-old boy with stab wounds to his chest and side, and another who had allegedly been hit on the head with a bottle.

The boy with stab wounds has undergone surgery at Royal Prince Alfred Hospital and remains in critical but stable condition.

The other boy was also treated at the hospital.

Officers arrested a 16-year-old boy, after he received treatment for a head wound at Concord Hospital.

He is being questioned at Burwood Police Station.