Seventeen people have escaped injury after two hot air balloons landed next to a motorway and a backyard in Melbourne's eastern suburbs this morning.

Key points: Both balloons landed at separate locations about 8:00am

Both balloons landed at separate locations about 8:00am A witness said one balloon crashed through gum trees behind her back fence

A witness said one balloon crashed through gum trees behind her back fence The company operating one of the balloons said an unexpected wind change forced a "drag landing"

Ambulance Victoria said one balloon was carrying nine people when it landed near the intersection of High Street Road and Eastlink in Wantirna South about 8:00am.

At the same time, another balloon carrying eight people landed in Terrara Park in Vermont South, with part of the balloon falling into a neighbouring backyard.

Paramedics have assessed people who were on board the balloons and said nobody was injured in either landing.

One balloon was left partly hanging over a Vermont South backyard. ( Twitter: Ariel Merida )

'They looked like stunned mullets'

Christine Taylor, from Vermont South, told Melbourne radio station 3AW the balloon appeared to be carrying Chinese tourists and landed next to her back fence.

"The balloon is over our fence into our pool, all I could hear was the crashing of the gumtrees as it hit," she said.

"The balloon is huge, just near our pergola.

"It was the scariest thing, I thought it was an earthquake or a big gumtree coming down, and then bang, the thing hit and the balloon was over our fence.

"I'm still shaking actually, it was really, really scary plus I was worried, because of the impact, maybe people have been hurt.

"I flew down in my pyjamas to see if the people were all right.

"One lady fainted, but the rest, they looked like stunned mullets."

Christine Taylor was in bed when she heard the hot air balloon crash into her backyard. ( Supplied: Christine Taylor )

Wind change behind unplanned landings

The balloons were part of a formation which took off at dawn from Bundoora, in Melbourne's north, aiming for the Moorabbin Airport.

Commercial Hot Air Ballooning Industry spokesman Damian Crock said the balloons were under the control of experienced pilots.

He said wind conditions changed about 90 minutes into the balloon flights.

"Both pilots report experiencing a significant change in wind direction and speed from N through NW to W," Mr Crock said in a statement.

"The pilots chose safe landing sites and both flights have been concluded without injury.

The pilot of the balloon which landed in Vermont South was forced to do a "drag landing" because of significant ground wind speed.

"The other balloon landed … in a horticultural property which resulted in minor damage to a small tree."

'The problem with flying over cities'

Kiff Saunders is the director of Global Ballooning Australia, which operates the balloon which landed at Vermont South.

"It was a drag landing that just dragged a bit too far, that's the problem with flying over cities, there's not as much space," Mr Saunders said.

He said he was flying another of his company's balloons this morning when a wind change arrived earlier than ballooning pilots had expected.

"It's one of those unfortunate situations, but no-one was injured," he said.

"It is an adventure sport and these things happen."