A gatecrashed party in Sydney at the weekend ended in two stabbings after dozens of people went to 'war' with officers who attended the chaos.

A man and boy, aged 19 and 17, were stabbed during a 70-person brawl outside a home on Zephyr St at Austral, in southwest Sydney, about 12.50am on Sunday.

Emergency services were called to the scene following reports of the stabbings and were met with a 'chaotic scene'.

A group of gatecrashers had ruined a party at an Airbnb on the street, arriving shortly after midnight.

The party hadn't been advertised online but its details were leaked on Snapchat.

Officers arrived at the scene and were unable to locate the two stab victims, who were later found in separate vehicles on nearby streets.

Detective Inspector Scott Houldin said police were forced to use pepper spray on the wild crowd.

Footage showed the officers attempting to fight multiple people off at once, with one officer seen tackling a woman to the ground.

'I have seen some CCTV this morning which depicts that chaos and that will form part of our inquiries,' Inspector Houldin said.

He added officers who responded to the scene were forced to 'protect themselves'.

'We encountered some pushback by those involved and they weren't assisting police in their inquiries,' he said. 

Residents on Zephyr St were rattled by the brawl with one telling 9News it was like a 'war' and another saying they'd 'never seen anything like it'.

Officers found the first stab victim, the 19-year-old, sitting in a vehicle on Browns Road with stab wounds to his torso.

The second victim, the 17-year-old, was in a vehicle on Fletcher Street with stab wounds to his thigh.

Both were invited guests to the party. They were taken to hospital and assisted police.

Multiple crime scenes were established and officers recovered three knives, as well as 'other exhibits'.

The recovered items will undergo forensic testing.

No arrests were made in relation to the stabbings and Inspector Houldin appealed to the public for information.

'Anyone with dashcam, CCTV and mobile phone footage to identify those who attended the party last night and caused the brawl and the subsequent stabbings,' he said.

The five-bedroom Airbnb prohibits parties and is advertised as a 'family getaway'.

The host claimed the guests requested the property's security cameras be turned off on the night of the party.