Helicopter tours over the famous Gold Coast on Australia's east coast have ended in tragedy: two helicopters collided in mid-air early Monday afternoon near Sea World theme park.
At least four people were killed and three others are in critical condition, police spokesman Gary Worrell said.
According to initial findings, one of the helicopters had just taken off and the other was about to land when the rotors came into contact.
A helicopter then crashed and landed upside down on a sandbank in the sea.
Numerous pieces of debris could be seen in the pictures.
The other managed to land, but the windshield broke.
Six occupants were injured by broken glass, it said.
The accident happened near Sea World Marine Park on Main Beach.
According to reports, the helicopters belong to the theme park and have been used for sightseeing tours.
Sea World was "shaken by what happened," a spokesman said.
"Our sincere condolences go to everyone involved and in particular to the relatives and families of the deceased."
An "unimaginable tragedy"
A large contingent of police and paramedics were deployed.
An eyewitness told the broadcaster 9News: "I don't know exactly what happened, but there was a massive bang." Queensland Prime Minister Annastacia Palaszczuk spoke of an "unimaginable tragedy".
Immediately after the accident, people on boats and jet skis rushed to help those affected, the AAP news agency reported.
How exactly the collision could have happened was initially unclear.
The Australian Transport Safety Authority began investigations.