A Jetstar plane has been forced to return to Melbourne Airport shortly after take-off because two flight attendants became sick, the airline says.
Flight JQ 772 took off about 11:45am bound for Adelaide, but the captain made the decision to divert back to Melbourne.
The Airbus A320 touched back down about 12:15pm and paramedics treated the two crew members at the scene.
A Jetstar spokeswoman said the pair was taken to hospital for observation, and each was in a stable condition.
But the airline could not provide further details on what caused the sudden sickness.
The spokeswoman was unable to substantiate a report the pair was overcome by fumes.
But it is understood the two flight attendants started feeling unwell after noticing an unusual smell in the cabin, potentially caused by residue from cleaning products.
The airline said engineers will inspect the aircraft and passengers have been delayed by about four hours.
No other passengers or crew were reported unwell, the airline said.