Theories relating to the unexplained noises have claimed they could have been caused by meteors or even spy planes.
Described as sounding like “distant fireworks”, the noises were heard across the UK between 9pm and 11pm on Saturday.
Alexander Macaskill on the Isle of Skye said the bangs sounded like high-calibre gunfire, similar to ship or jet cannons.
The noises were also heard 3,000 miles away in New York at the same time, with people taking to Twitter to complain that their windows had been rattled by the vibrations.
People in Denmark and even Sydney also reported hearing strange sounds, with Anne SPN Svendsen tweeting: ‘Seriously some heard those mysterious #loudbangs this weekend here in Denmark!!’
And this afternoon, a user named Sally Mueller implied that more noises had been heard in Sydney, tweeting: ‘What the hell was that?! #loudnoises #sydney #innerwest #loudbangs’
One theory that has emerged is that the bangs heard over the weekend could have been caused by a meteorite breaking up in the atmosphere.
A Twitter user, posting under the name Virtual Astronomer, said that material from space entering the earth’s atmosphere could also be responsible.
He told MailOnline: “Space debris such as old satellites and things can cause sonic booms heard over very large areas.
“It’s the same for big meteors or rocks that come in.
“There are also some rare meteorologic phenomena that can cause rumbling or bangs apart from thunder.”
However, experts have said that there was only one piece of debris from the ruined Russian satellite Kosmos 2251 scheduled for re-entry.
Science writer David Dickinson said that the timing was “not a good fit” for it to have been over the UK.
He added: “I do not think it was a meteor or a piece of space junk, as the noises mentioned spanned a large segment of time.”
It was suggested the noises could have been sonic booms from RAF jets flying in the area.
But the Ministry of Defence said it had no record of any planes being scrambled at that time.
Conspiracy theorists have also claimed that the sounds could have been made by a spy jet powered by a ‘pulse detonation engine’.
Another popular theory was that the sounds were caused by systems such as space weather, electrical or severe thunderstorms.
The Met Office, however, said there had been no reports of that kind of weather.
Claudia Angiletta, 27, said that she was watching television at home in London when she heard the unexplained sounds.
They lasted for more than half an hour.
She said: “It was very distracting as it went on for ages.
“I went out to look for fireworks but I couldn’t see anything in the sky.”
Some people took to social media to expound more extreme theories.
One Twitter user, named “Mr M”, claimed the loud bangs were “controlled explosions following a foiled terror plot with controlled media coverage to prevent mass panic”.