.
Staff helped evacuate passengers via three slides at Sydney Airport, Australia Credit: Channel 9 News Paramedics helped the injured, and those who were affected by the fumes Credit: Channel 9 News Aswin De Silva said: "I landed on my elbow and I saw blood gushing out."
Two other passengers were treated for wounds sustained from using the slides, while others reported itchy throats and sore eyes.
Dramatic videos show the panicking passengers throwing themselves down three slides after smoke filled the cabin.
HYDRAULIC FLUID LEAK Qantas said that engineers are "working to determine the cause of a hydraulic fluid leak on board one of its Airbus A330s.
"AF575 departed Sydney for Perth at 8.45am this morning.
"Approximately 20 minutes into the flight, the captain received a cockpit alert for one of three hydraulic systems on the aircraft."
The airline said that once the aircraft was back on the gate there were reports of a thick haze in the cabin, likely caused by hydraulic fluid entering the air conditioning unit.
"While customers may have thought it was smoke, there was no fire.
"Two passengers were treated for injuries sustained from using the slides and another passenger was taken to hospital as a precaution.
"Some customers reported sore eyes and itchy throats."
Qantas Fleet Safety Captain Debbie Slade added: “We’ll investigate exactly what happened, including liaising with Airbus, before this aircraft is returned to service."
Three slides were used during the evacuation Credit: Channel 9 News Global flight tracking service Flightradar 24 shows how the Qantas plane returned to Sydney Credit: Flightradar 24