A pair of UFO videos showing remarkably different craft have been viewed thousands of times in the past couple of weeks.
In one clip, uploaded to YouTube on Saturday, a cigar-shaped object can be seen flashing in and out of vision above the US city of Greensboro, North Carolina.
"Yesterday while walking around outside looking for birds to film and photograph I noticed a strange flashing light in the sky near an airplane," Bret Jones wrote on YouTube.
"It was moving slowly in the sky, a little slower than the planes flying around."
Being so high, Mr Jones said it was difficult to focus on, and he wasn't sure if he'd caught it until reviewing the footage afterwards.
- UFOs in New Zealand: What Kiwis see in the skies
- UFO filmed 'feeding on lightning'
- NASA shows off photo of 'flying saucer from outer space'
The object looks somewhat like a bullet, with a grey-blue middle and copper-tinged ends. At one point it appears to be ejecting some kind of substance, before appearing to "warp" out of existence, as one viewer wrote.
Others said they've seen similar sights in North Carolina in the past, which have often been written off as blimps, according to local paper the Charlotte Observer.
And in a more down-to-Earth security camera clip shot in Doncaster, UK, a very bright light can be seen landing in someone's front yard.
"Aliens exist and now living in my 10-ton sand pile on the drive way," YouTube user Tiho Gro wrote. "Maybe this weekend will dig the sand to find them and make the first contract [sic]."
- 'Cigar-shaped' UFO in Texas mystifies internet
- Meet New Zealand's very own UFO maker
- Audio: Multiple pilots report UFO flying over Ireland
The sheer brightness of the UFO - which stands for unidentified flying object - led to suggestions it's simply a Chinese lantern.
Chinese lanterns are regularly blamed for UFO sightings.