An eyewitness who owns a shop inside the market also told reporters that he heard a loud explosion, with a ball of fire and clouds of smoke in its aftermath.
VOA: standard.2009.06.01
He turned to see a plume of white smoke rise, when suddenly another explosion followed, doubling the smoke.
The blaze was discovered at 16:50 BST by a police officer who noticed "a large amount of smoke and heard an explosion on some wasteland near to the travellers site".