Two English tourists have been attacked by a shark near Airlie Beach in Queensland's popular Whitsunday Islands.
One man, 28, had his foot bitten off by the shark and the other man, 22, suffered severe calf lacerations.
They were snorkelling on a ZigZag Whitsundays boat in the Hook Passage when they were attacked around 10.20am.
There were 20 other people on board the boat, although it is unclear how many people were in the water at the time, or what the species of shark was.
The pair were brought by boat to the Coral Sea Marina about 11am, where they were treated by paramedics.
"There is one patient with quite serious foot injuries," the ambulance service said.
The other has a lower leg injury.
The RACQ Rescue Helicopter will transport them to the Mackay Base Hospital.
The Whitsundays region has been the site of a number of shark attacks in the last year.
Victorian man Daniel Christidis, 33, died in November 2018 after being attacked at Cid Harbour at Whitsunday Island during a trip with friends and colleagues.
That incident followed separate attacks within 24 hours in September - also at Cid Harbour - on Tasmanian woman Justine Barwick and Victorian 12-year-old Hannah Papps.
Earlier this year a man was hospitalised after being bitten on the thigh in waters at Hardy Reef, about 50km northeast of Hamilton Island.
