Houses are being evacuated near Queenstown after a digger ruptured a gas main.
A St John Ambulance spokeswoman said one person was assessed at the scene on Cherry Blossom Ave, in Frankton, but did not need to be taken to hospital.
A man at the scene said police were evacuating houses around a 300 metre perimeter.
"It's maybe 50 houses ... they're knocking on doors."
Other people had been told to stay inside.
A large cloud of grey-white gas is visible near a house.
Firefighters in protective breathing gear can be seen hauling heavy duty hoses.
At least two fire trucks have responded as well as several police units.
A police spokesman said they were called at 9.30am. They were helping with a roadblock.
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