The first authorities heard of the balloon crash at Pokolbin, which occurred about 8am in heavy fog, was after Cessnock hospital notified paramedics nine people presented to the hospital for treatment.

But Matt Scaife, the director of Balloon Aloft, which owns Balloon Safaris, said reports there were serious injuries after the “firm landing” were a whole lot of hot air, stressing “everybody disembarked the balloon as normal”.

Mr Scaife said the pilot made a decision to end the flight after 30 minutes due to poor visibility.

“He made a decision to approach down as normal,” he said. “Unfortunately, he misjudged the approach and hit some trees. He was able to land the balloon safely.”

Brisbane tourist Michael MacGregor said the pilot told the occupants to brace themselves as the balloon touched down in a paddock on the corner of MacDonald and Broke roads.

“The pilot said, ‘brace yourself, brace yourself’ as we hit the top of the tree and spun around at 360 degrees,” Mr MacGregor told Nine News. “People were screaming. We were about 10 metres above the ground. A lot of tree branches were over the road.”

He added: “We hit the top of the gum tree, spun around, hit another gum tree ... and then we slammed into the paddock.”

A nearby witness said he rushed over after hearing the balloon come down. 

“It was foggy but I could hear the burners and thought that sounds too low,” he said. “The next minute it hit the trees.”

NSW Ambulance Inspector Luke Wiseman stressed that paramedics should have been called, confirming nine patients presented to Cessnock hospital for minor injuries, while two were transferred to John Hunter Hospital for spinal assessments. 

Those injured were aged between seven and 38, paramedics said.

Hunter Valley police Inspector Rob Post said the Australian Transport Safety Bureau would be conducting an investigation. When asked whether triple-zero should have been called, he replied: “I think it would be common sense to make that call.”

Inspector Post said the removal of the balloon after the flight may have hindered an investigation.

It is the second hot air balloon crash involving the same company after a sudden wind change was believed to have caused a balloon to crash near Greta in January. Balloon Safaris later said in a statement the pilot was highly experienced with 3000 hours’ commercial flying time. 

The company said the pilot did not believe there was a need for emergency services to be called.

It said hot air ballooning was considered “one of the world’s safest forms of aviation”.