A wartime bomb has exploded days after a complex defusing operation had begun.
It has been confirmed that it was not a planned detonation in Great Yarmouth, Norfolk.
Police evacuated homes and businesses after the discovery the town earlier this week.
The force have announced that the explosion was not arranged after they changed their approach to safely detonating the bomb.
They tweeted tonight: "We can confirm the unexploded World War II bomb in Great Yarmouth has detonated.
"This was not a planned detonation & happened during slow burn work to disarm the explosives. All army & emergency service personnel are accounted for. We will bring you further info when we have it."
The bomb was found at Bollard Quay on Tuesday lunchtime.
A massive protective sand barrier was built around it to minimise any damage from any blast.
The team in charge of the operation abandoned attempts to cut through the bomb's outer casing yesterday.
Reports suggest a metre-long Second World War device was discovered in the River Yare on Tuesday.
Norfolk County Council state the suspected bomb was found by a contractor working on the new river crossing.
Jack Onyett, who lives opposite the quay where the bomb went off, told ITV news it was a "very scary" experience.
He said: “When it went off I was a bit worried because my house is so close. I was more worried about my house going up.
"Now it’s all over hopefully we can get back in the next few hours.
"It was very scary. Not many people have seen a World War Two bomb blow up and it was very scary.”