Sydney teen found with rifle in backpack

A teen who allegedly tried to flee from police in southwest Sydney has been charged after a shortened firearm was found in his backpack.

The 17-year-old male allegedly ran from a property at Airds when police arrived on Sunday afternoon to arrest another 17-year-old over outstanding warrants.

The teen jumped a fence before police, with help from the dog squad, arrested him.

Officers searched his backpack and found a shortened bolt-action rifle, ammunition and stolen property.

The other teen at the home has been charged with several offences including assaulting police and break and enters.

Both teens were refused bail and are due to appear at Children's Court on Monday.