People in Kent have been left scratching their heads after low-flying planes appeared to nearly skim trees and electricity cables.
Many in the east of the county have reported seeing large aircraft swooping so low they feared they might crash over the last week.
One golfer, preparing to tee off, said he thought it was going to crash.
"I've honestly never seen anything like it - it was like you could almost jump up and touch it," he said.
"It wasn't even flying straight - it was more at an angle. I genuinely thought it was going to crash into the field next to us."
On Monday, photographer Jack Huckstepp, 18, was shocked to see a plane swoop down over Chilham and rushed to snap a photo.
"It was very loud and it was a sound that you could feel as it went over," he said. "From where we were it looked not much higher than the tree tops."
Jack took to Facebook to share his "one in a million" photo.
One social media user said: "We saw it by the school in Chartham and for a second thought we were witnessing a crash!"
"Saw it along the A28 between Kennington and Wye just as low," said another, while one man said the sight left him "in absolute disbelief".
The sightings sparked a great deal of curiosity, with many wondering why the planes were operating at such a height.
But the RAF has now confirmed pilots were taking part in low-flying exercises.
The lower limit for such training is 250ft above ground level, which the RAF says the planes adhere to throughout the training.
A spokesman said: "Members of the public who are not familiar with the size of RAF aircraft often believe aircraft are much lower than they actually are.
"The RAF aircraft identified in Kent, were Hercules C-130 and Atlas A400M from RAF Brize Norton completing routine essential low flying training which remains vital for our aircrew to achieve and maintain operational effectiveness."
The MOD provides a Low Flying Complaints Enquiry Unit and takes complaints about low flying aircraft that has caused concern very seriously, but says it has not received any complaints relating to the Kent training, which it says was conducted within flying rules and regulations.