An unusual phenomenon described as a ‘mini tornado’ created confusion and concern among locals who saw grass flying in the air above the tree line.

Many residents of Royal Wootton Bassett told the Adver they couldn’t believe their eyes when they spotted the event near Sally Pussey’s Inn.

“I saw driving so couldn’t stop to video it, but I thought I was seeing things,” said Darren Gillam, of Drain Developments, who described it as a ‘mini tornado’.

“The grass was twirling about 20ft high.”

Kimberley McColl, who was also driving towards the roundabout between Sally Pussey’s Inn and The Churchill said she saw the phenomenon at around 1.35pm on Thursday, June 20.

“It was happening in the field directly behind the roundabout and I was really confused.

“There were huge clumps of dry grass being blown in a circular motion about 20-30 ft in the air, well above the trees lining the road.”

The similar incident to the one described has been spotted in BrinkworthThe similar incident to the one described has been spotted in Brinkworth (Image: Alison Christie)

She added: “I could still see it in the rear view mirror a fair way down Swindon Road.

“I think I just assumed the farmer was cutting down the field using an industrial sized leaf blower to clear the mess.”

Residents who took to social media have described the event as a 'whirlwind', 'mini tornado' and 'grass storm', and although no official cause has been confirmed, Paul Knightly, Head of the Tornado and Storm Research Organisation believes the flying grass was an example of a 'dust devil' or 'hay devil'

The weather incident was spotted from the road next to The ChurchillThe weather incident was spotted from the road next to The Churchill (Image: Newsquest)

According to the Met Office, a dust devil is "an upward spiralling, dust filled vortex of air that may vary in height from a few feet to over 1,000.

"They are usually several metres in diameter at the base, then narrowing for a short distance before expanding again. They mainly occur where the ground is dry and high surface temperatures produce strong updrafts.

"Unlike tornadoes, dust devils grow upwards from the ground, rather than down from clouds."

These can come in various forms, including 'hay devils' which happen near farm land in really hot weather.

"I’ve seen it several times before down the hill a bit," said Bassett local Alex Hutchings.

"The way the wind blows round the hills makes it do it. If the grass wasn’t so dry then you wouldn’t have been able to see it.

"You normally see it in hot weather when it’s dusty."