© The York Press
Jonathan Tyler contacted The Press to say the 'explosion' happened at about 9.10pm last Sunday evening in the Fishergate area, and it was enough to bring many people in Sandringham Street out into the road.
"There had been a smaller explosion several hours earlier," he said. "To my surprise, nothing has been reported in The Press or elsewhere to my knowledge.
"It seemed to us much louder than a car backfiring, and if it was a vehicle collision The Press would surely have heard about it - there were two 'explosions'. I did wonder about a sonic boom - we have the constant rumble of high-level military flights."
Another resident, Ben Rich, said: "I heard it too and also came out to see if there was anything to see - it did sound very loud.
"Looking on nextdoor.com, it was also clearly heard on South Bank. The speculation seems to be fireworks echoing off the river or a sonic boom, although an odd time of night for that."
