Puzzled homeowners took to social media with speculation it could have been caused by falling meteors, fighter jets or even aliens in UFOs.
A man in Ilford, east London, recorded the noises and flashes of light at about 11pm, saying his home shook as if an earthquake had struck.
He said in his film: “I have a theory that it was a meteorite.
“If it had been a land-based explosion there would be damage somewhere but so far no damage.
“It was too loud to be a firework that’s for sure and fireworks don’t shake houses. I don’t think it’s a supersonic aircraft as a sonic boom does not give off light.
“I think it was a meteorite burning up in the atmosphere. This would give off light and cause a sonic boom.”
Yet, The Royal Observatory at the Royal Museum of Greenwich has dismissed this speculation.
A spokesman said: “This doesn’t have the character of a meteor, since such a blast would only occur after a sustained bright light during atmospheric entry – not a quick flash as shown in the video.
“It’s also somewhat unlikely that three blasts would be heard. It looks and sounds a little bit more like a firework.
“An object would only be classed as a meteorite if it actually reached the ground – something up in the air like this would be a meteor.
“Our understanding of large meteors and fireballs is that, although they can produce sonic booms and/or loud bangs (in the latter case when they fragment violently), they are more likely to produce a sustained glow for several seconds (which may vary in brightness) as they move across the sky, rather than a single, momentary flash.”
Other witnesses debated the cause online.
Many said it could be a fighter jet breaking the sound barrier, but some felt the more out-of-this world UFO suggestion was more likely.
Sam Smart heard the explosions from Wanstead, four miles from Ilford.
The 24-year-old wrote: “It was too loud to be a firework. It sounded like the sonic boom of a jet to me.”
Another resident in nearby Woodford said the loud bangs were like gunshots.
One Twitter user wrote: “Just heard three loud booms, like an explosion here in East London. Anyone know anything?”
A spokesman for the Ministry of Defence said: “We know nothing about it. A sonic boom would suggest there was a foreign plane in our airspace, which was not the case.”
No jet had been scrambled in the UK either.
A Metropolitan Police spokesman also confirmed that the force had received calls, but was not investigating.
Nick Pope, who once investigated unexplained UFOs for the MoD, said: “I’m sceptical about the fighter jet theory, as night flying by military jets over built-up areas is unusual, and my understanding is that supersonic flying over the mainland UK is not allowed, in view of the disturbance caused.
“I think the meteor theory is quite likely. Meteors and fireballs entering the Earth’s atmosphere at high speed would produce a flash of light and can also generate sound, in the same way as an aircraft can generate a sonic boom.
“If it was a large one, it could split into pieces, which would explain why three flashes were seen. Meteors and fireballs turned out to be the explanation for several spectacular UFO sightings that I investigated while working on the MoD’s UFO project.”