Joburg explosion | Call to implement regular gas safety checks

JOHANNESBURG - The search is still on for the exact cause of the Joburg CBD explosion.

City of Johannesburg authorities started the process to have it declared a local state of disaster.

The explosion damaged roads and other infrastructure.

READ: Joburg gas explosion | City manager says City waiting on more tests

In an update, the Joburg City Manager said investigations are continuing into the cause of the blast.

Head of Fire Engineering at Stellenbosch University, Richard Walls, says regular testing is crucial.

"After this incident, all the companies having gas lines around the area would have rushed in and shut everything down and moved pieces.

WATCH: City of Joburg gives update on CBD explosion

"So firstly, if there was a leak maybe we won't know because what was leaking has been shut off or removed and then they won't find it," he said.

"If what was causing the leak has been dealt with then we are fine, but we need ongoing gas measurements into the tunnels.

"To my understanding, this network runs throughout Joburg under the streets so we need regular gas detections throughout the different spaces."