Two children are dead after a freak jumping castle accident at a fair in China, with a dust devil flinging the inflatable structure around in the air before sending it crashing to the ground.

Key points: An unexpected dust devil hit a fair in China, causing havoc

An unexpected dust devil hit a fair in China, causing havoc People were picked up along with the jumping castle before falling back to the ground

People were picked up along with the jumping castle before falling back to the ground Two children died after hitting concrete, but others landed in trees

At least 22 people were also injured in the incident on Sunday afternoon (local time) at a pear orchard in Yucheng County, Henan province.

Video of the incident shows the dust devil approaching before the jumping castle is lifted up and spun around.

People can be seen bracing against the wind and ducking for cover as the wind hits and items are lifted off the ground.

One other child was left in a critical condition, according to a statement from the Shangqiu City Government.

Dust devils are not usually considered dangerous, but can sometimes become large enough to threaten people. ( Weibo: Subaoge )

"Twenty two people were injured, including two children who died after ineffective emergency treatment, and another child was severely injured and transferred to the intensive care unit," the statement read.

"The surgery for this child was completed successfully, while the [other] 19 people remain in a stable condition."

The dust devil struck when there were more than 400 people attending the fair, which is held every year when the local pear trees are in blossom.

Chines media reported the weather event only lasted a few minutes before it dissipated.

The children who died fell onto concrete according to the statement, while the others fell into tree branches and mud and escaped with less serious injuries.

The jumping castle is flung through the air during the incident. ( Weibo: Subaoge )

Dust devils are small whirlwinds caused by hot air near the surface rising rapidly through cooler air above.

Reports of injury and fatalities are uncommon.