Two large blasts - described as too loud to be fireworks - were reported in the early hours by people living in Sheffield.
Now more people have come forward to say they too heard the noise in Doncaster - twenty miles away.
Others have posted on Facebook that the explosions were also heard in Mexborough - and readers have speculated that the noises may have been caused by low flying aircraft, roadworks or sonic booms created by high-speed jet planes.
However, some have reported hearing the blasts close to midnight while others said they heard the explosions at around 4am.
Jennifer Fogg from Sheffield said: "I heard a bang around 4am - I only heard one tho and I'm on Manor."
Hollie Guest added: "I heard two loud bangs last night near enough about midnight."
And Marie Watson posted: "Ah so I wasn't imagining it. I heard it - must've been 4am-ish scared the life out of me."
Others reported being woken up by the noises while Janet Oxley posted on Facbeook:" I heard a very loud low plane at 3am going over S6."
Melanie Neale reported hearing the noise at around 1.10am and said: "It sounded like a huge explosion in Mexborough. I listened for the sirens expecting to hear them but didn't.
"I thought at that point it's a sonic boom but heard no aircraft - maybe it's the aliens!"
Sandie Timms wrote: "I heard one loud bang in Doncaster it woke me from my sleep and Liam Higgins said: "I heard this too. Said it was too loud to be a firework."
Chris Tucka added: "I only heard a loud over head jet or some kind and couldn't work it out at first in Doncaster."
The two blasts were reportedly originally heard in Handsworth, Manor and Sheffield city centre in the early hours, with people taking to social media to report the noises.
Facebook user Cheryl Hague said: "A lot of people are talking about hearing two loud bangs in Sheffield during the early hours of today.
"Social media reports suggest they were heard in Handsworth, Manor and city - far too loud to be fireworks."
It comes a few months after a mystery early morning blast which was heard by people across South Yorkshire and up to 30 miles away.
The "massive bang" in April was supposedly heard in the Rotherham and Meadowhall area - but there were no reports of fires or explosions in the area.
After we reported on the blast, others came forward to say they also heard the noise - with one saying it was reportedly heard in Saddleworth between Sheffield and Manchester, more than 30 miles away.
It is not the first time South Yorkshire residents have been left puzzled by mysterious explosions.
Last October, residents in Long Sandall, Doncaster were left baffled by a massive late night noise with no obvious signs of what had caused the explosion or evidence of damage.
Andrew Hill said: “I felt the whole house shake and windows were rattling.'¨“I went outside and could see smoke near the rail crossing but there were no obvious signs of what had happened.
And in November 2014, several loud 'mystery bangs' that shook windows baffled people across the country. Dozens of Twitter users from London to Glasgow claimed to have heard the strange noises, which sounded like fireworks or loud aircraft.
And in May this year, two huge sonic booms were heard across Doncaster and huge swathes of northern England after two RAF fighter jets were scrambled to intercept an Air France plane flying into Newcastle Airport which had lost contact with air traffic control.
The mystery blasts came just hours after a United States Air Force pilot was suspended from flying after breaking the sound barrier over Norwich yesterday.
The sonic boom, which occurs when an aircraft travels faster than the speed of sound, happened at 1.40pm yesterday.
A spokesman for RAF Lakenheath airbase said the aircraft involved was an F-15C Eagle, assigned to the 48th Fighter Wing.
He said there will be an investigation into the incident and the pilot will complete further training.