Residents and business people in Johannesburg's inner city say they were left traumatised by Wednesday's mystery explosion beneath a busy street.
'I felt my intestines go cold from fear. I have never witnessed something like that before," said Thembelani Mutunwa on Thursday.
"As pandemonium engulfed this part of the city, the first thing that came to my mind was that it was an earthquake or one of the buildings around us collapsing."
Mutunwa, who sells sweets along Lilian Ngoyi Street - formerly Bree Street - was right there when the powerful blast ripped through the road on Wednesday afternoon.
He described moments of confusion where people couldn't figure out what was happening.
"The first reaction for many was to run away from the scene, but some were also curious and they began gathering and taking pictures with their phones," said Mutunwa.
The explosion was initially assumed to have been caused by an underground gas leak. On Thursday, however, Gauteng Premier Panyaza Lesufi said a preliminary report suggested that issues with three underground junction boxes - enclosures housing electrical connections - might have been the cause.
"We have three possible scenarios here... we might have a gas problem, the cause might be lithium, or illegal mining activities," said Johannesburg Emergency Services (JES) spokesperson Robert Mulaudzi.
He warned onlookers to stay away...
