The scene of the explosion at Denel near Somerset West. Photo: Phando Jikelo/African News Agency (ANA)

Rheinmetal Denel Munition chief executive Norbert Schulze says they cannot confirm yet how many people died during Monday afternoon's explosion at the plant near Somerset West. 

It was believed that eight people had died, but the number of people who sustained injuries is also still unclear. Being a National Key Point, information isn't freely available and it's still unclear what had caused the blast which rocked surrounding areas.

Schulze told the SABC the building where the explosion took place is being searched today to locate the bodies of those who had died and to assess structural damage. The building in which the explosion took place is used for mixing propellants for artillery chargers.

“We have no idea what the cause was of this incident. The investigation will probe deeper. It is a devastating explosion that happened there."

News24 reported that around 100 people gathered at the depot entrance on Tuesday morning to pray, sing and place flowers against the boundary wall as they paid their last respects to those who died.

The family of Jason Hartzenberg, 21, sobbed and held each other as they waited for answers outside. He had been working at the munitions factory for just three months.

His aunt Marilyn said he was their sole breadwinner and they were struggling to come to terms with what had happened.

The 41-year-old Nico Samuels's wife, Lawrencia, who lived nearby, confirmed that her husband was one of the staff who had died.

"I tried to find out what had happened, but nobody gave us any answers. A number of people were already there. Then they started calling names, asking relatives to go to the boardroom. That's when I knew something was wrong," she said.

Macassar resident Sophie Abrahams heard the blast and rushed to her 71-year-old uncle in Marvin Park, neighbouring the factory.

“I heard the blast faintly and then the earth shook beneath me briefly, and as I went out, people said it was the factory.

‘‘My uncle is a pensioner and lives right next to the factory, and I rushed to make sure he and his daughter were safe. Thank God they were.”

Abrahams said despite initial reports and much confusion, authorities did not evacuate the area.

The SA Federation of Trade Unions was shocked and angered by the death of at least eight workers, urging "that everything possible is done to find the further six workers believed to be still missing".

"The factory produces explosives and propellants for civilian and military use in ammunition. Given the extremely dangerous products being manufactured at the factory, the federation demands an urgent and full investigation into this cause of the accident, to check whether all health and safety regulations were being observed in the factory and, if not, to find those responsible.

"The safety inspectors must also look into what additional measures are required to tighten safety rules and ensure that such a tragedy is never repeated."

City Fire and Rescue spokesperson Theo Layne said their members responded around 3.45pm.

“On arrival, it was ascertained that an explosion had occurred and staff of the factory were extinguishing the subsequent fire. Eight people are confirmed dead.”

Layne said 15 firefighters with three fire engines responded to the scene.