More than 17,000 people would perish if North Korea dropped a hydrogen bomb in the centre of Epsom, a computer programme has revealed.

North Korean officials this week claimed the state had conducted an underground hydrogen bomb test.

Nukemap, a computer programme which predicts the fallout from such an attack, projected 17,730 fatalities and 35,970 injuries if the bomb had a ten-kiloton yield, as it claimed in 2013.

The blast’s 150-metre radius would see the town centre decimated, yet it looks as if the famous Epsom Downs racecourse would survive, as would Ashtead, Banstead and Leatherhead.

In the image above, the colours have the following (deeply disturbing) meanings:

Green - Without medical treatment, there can be expected between 50 per cent and 90 per cent mortality from acute effects alone.

Dying takes between several hours and several weeks.

Grey - Most residential buildings collapse, injuries are universal, fatalities are widespread.

Orange - Third degree burns extend throughout the layers of skin, and are often painless because they destroy the pain nerves.

They can cause severe scarring or disablement, and can require amputation. 100 per cent probability for third degree burns.