At least six people have been injured in a serious hot-air balloon accident northeast of Melbourne this morning.

Paramedics are treating the injured after the hot-air balloon came down near the Yarra Valley at Dixons Creek.

The Go Wild Ballooning craft came down in Bleases Lane at 7am.

A spokeswoman for Ambulance Victoria said paramedics are assessing six people

Reports suggest the hot air balloon stalled at 500m before coming down hard. Multiple people were ejected from the aircraft.

Images from the scene show passengers lying on the ground being treated by emergency crews.

9NEWS reports that 15 people were on board and at least seven have neck and back injuries.

Witness Dean Fuhrmann told the Australian he was driving in the area and saw two balloons.

"One of them looked in trouble," he told the newspaper. "It looked like it was getting blown quite a lot. The basket was hanging, tilted a bit, and it was a bit gusty. Then two cop cars went past quickly, heading out. It just didn't look right."

A number of people are being treated by paramedics after a hot air balloon incident near the Yarra Valley at Dixons Creek @7NewsMelbourne pic.twitter.com/dfuQxqDfrm

— Melina Sarris (@MelinaSarris7) February 7, 2018

Another witness told 3AW they saw the basket on its side.

"It's a huge open field. The recovery vehicles were there," he said.

"I saw the basket was on its side."