WATCH: World War II bomb unexpectedly detonates in England

A World War II-era bomb unexpectedly detonated while crews were working to diffuse it.

The bomb went off Friday in Great Yarmouth, England. 

First responders declared a major incident after the 250-kilogram unexploded device was discovered in the River Yare on Tuesday. 

That's when the military officials came in Thursday to work on disarming the bomb, but the device then exploded Friday, according to police. 

Drone footage by Norfolk Police captured the moment the bomb exploded.

Police said nobody was injured. 

Storyful contributed to this report. This story was reported from Los Angeles.