Gas experts have been called on to help investigate the cause of the explosion in the Johannesburg CBD.

Providing an update on the situation in Johannesburg, Gauteng Premier Panyaza Lesufi confirmed that road collapse was due to a gas blast but the cause behind it is still unknown.

Lesufi noted that experts have long been raising concerns over the stability of building in Rissik and Bree Streets. He adds that their main priorities now are to assess whether there could be another possible blast, and if there was any damage to buildings nearby.

The explosion claimed the life of one person and injured 48 others.