What WERE the loud bangs being heard across Britain? Twitter bombarded by reports of mysterious noises as military denies RAF jets were the cause Sounds reported last night from Glasgow to Croydon, south London Many suspected 'rumbling' sound was due to RAF jets' sonic booms But Ministry of Defence said none of its aircraft had been scrambled It came on same day mystery explosion forced closure of A1 roadÂ Britons have been left baffled by a string of 'loud bangs' which shook windows and disturbed children and pets from Glasgow to Devon to London. Hundreds of Twitter users reported the sounds between around 9pm and 10pm last night, but the Ministry of Defence said it did not know what could have caused them. Many suspected sonic booms similar to ones which shook Kent last month when two RAF jets intercepted a Latvian cargo plane in British airspace. Loud noises: People from Croydon (left) to Glasgow (right) were left baffled by a string of bangs last night But a Ministry of Defence spokesman told MailOnline she had no records of any jets being scrambled last night. The denial only served to fuel an outpouring of Saturday night speculation on social media. 100 shares Within minutes Twitter users had started spreading hashtags from the straightforward (#loudbangs) to the slightly melodramatic (#omgwereallgoingtodie). Many of the reports were picked up by Twitter user Virtual Astronomer, who said space debris re-entering the earth's atmosphere could have been responsible. 'Space debris such as old satellites and things can cause sonic booms heard over very large areas,' he told MailOnline. 'It's the same for big meteors or rocks that come in. Reaction: There was an explosion of activity on Twitter, where some users came up with their own theories There are also some rare meteorologic phenomena that can cause rumbling or bangs apart from thunder. The only other explanation could be supersonic aircraft. There was very little wind last night so conditions were perfect for sound to travel very long distances.'Â Dozens of the reports focused around Croydon, south London, where baffled Twitter users were asking each other what had happened. Others were heard in Bedfordshire, Glasgow, North Devon, Leicestershire and West Sussex. Dave Reed, who lives in Fareham, Hampshire, said his dogs 'went crazy for a couple of minutes' after hearing what he had assumed were fireworks. #Spooked: Was it an alien invasion, a meteor, the Third World War - or simply a few stray fireworks? The noises prompted conspiracy theories and immediate claims of a 'media blackout'. Twitter user Carrie Proctor wrote: 'This is how we'll find our that WW3 has begun. It'll be a Twitter hashtag long before any official announcement!' The 'explosion' sounds came on the same day a six-mile stretch of the A1 in North Yorkshire was closed due to reports of an explosion at 3am - whose cause has still not been explained. Police carried out extensive searches around the Marne Barracks at Catterick Garrison as the road remained closed. The searches included experts from the North East Counter Terrorism Unit, explosive detection dogs, the National Police Air Service and military search personnel.Â Shut off: A section of the A1 in North Yorkshire, which was closed yesterday after reports of an explosion The A1 runs adjacent to Marne Barracks, formerly RAF Catterick - the British Army's largest training facility