Terrified pedestrians reported hearing a 'huge bang' and a 'loud deep explosion' in Sheffield this morning.
Emergency services rushed to Glossop Road in Sheffield this morning after flames burst out from the ground in front of the Co-Op store.
Police have confirmed that that the cause of the 'explosion' was an underground electrical fire and have closed off a number of roads.
Pedestrians were seen walking past as the flames shot up from a manhole cover and said how they heard a 'loud, deep explosion'.
Nadia Powell was driving past at the time and said: "We were heading down the hill towards the coop at the bottom.
"The traffic lights were on red and we heard a loud deep explosion. Looking down hill we saw thick black smoke billowing from what looked like the front door of the Co-Op.
"We moved down the hill and there was a flame at time about 6ft tall from ground level.
"Pedestrians were everywhere and people were trying to catch it all on film, the police were quick to arrive and sort the traffic and the people to reduce injury or further problems."
Andrea Kirkpatrick was walking past at the time and said that pedestrians were left stunned.
She said: "I was walking down Glossop Road on my way to work at about 8.45. There was a loud bang/explosion and everyone stopped dead on the street.
"Then there was a weird roaring and gushing noise and flames shot up from the manhole cover outside the Co Op.
"There was a big burst of flame and smoke. People were a bit stunned but lots of students were still walking right past.
"I was concerned that, because it was gas, it could explode again. University security were on the scene pretty quickly trying to stop the traffic and within 10 minutes the fire brigade turned up."
Glossop Road and Clarkson Street are currently closed and police have urged people to avoid the area.