A large and unlit helicopter was spotted hovering at a low level in Shrewsbury, Shropshire on Tuesday night.
The bizarre moment was caught on camera when concerned onlookers scrambled to film the helicopter near Pride Hill at around 9:30 pm.
A video shows the helicopter hovering over several buildings in the area without its lights on.
Local police confirmed the chopper was not theirs leading speculation to grow over the helicopter and what it was doing.
Nearby RAF Shawbury later confirmed that the chopper was taking part in a training exercise - but were not involved themselves.
A spokesperson said: "There was training exercise over Shrewsbury last night – the airspace requirements were correctly advised.
"As RAF Shawbury were not involved we are unable to comment further."
Many online speculated that this helicopter was a Eurocopter AS365 Dauphin - linked to SAS 658 Squadron AAC.
Abdul Husen, 44, who filmed the video, was working in the nearby Cafe Saffron when the whole place started shaking.
He said: "I was at the restaurant on the third floor, all the windows were shaking at the back.
"I thought 'What the heck's going on?'
"The helicopters were circling below roof level. I'm sure there were two. Everybody said there were two. I could see one but heard two.
"I ran up the road as it was flying up the roads of Shrewsbury through the buildings
"At one point it looked like it was going to crash, it was unlit and in complete darkness.
"It flew in low under the radar they took some packages, they dropped something off on one of the buildings and then left at low level.
"It looked like some sort of special mission and there were loads of civilians about."
Abdul is a self-proclaimed aviation enthusiast and when the thunderous vibrations of the chopper shook Cafe Saffron - where he's worked for 23 years - he knew "exactly what was happening."
He said: "Nothing ever happens in Shrewsbury. This was like Christmas for me."
The Ministry of Defence (MOD) has been contacted for comment.
The footage was captured on September 12.
