Part of the Rheinmetall Denel Munition depot, at Somerset West, near Cape Town, South Africa, Monday, Sept. 3, 2018. Authorities say at least 8 people have been killed in an explosion at the munitions plant with investigators trying to determine the cause of the blast which shook homes and rattled windows in the area. (AP Photo)

Officials are investigating the cause of an explosion at the Rheinmetall Denel Munition RF(Pty) Ltd in Macassar, outside Somerset West, which claimed the lives of at least eight people.

Fears have also been allayed regarding the plume of smoke seen after the explosion on Monday afternoon. 

Disaster Risk Management spokesperson Mandy Thomas said: "After an initial inspection, Rheinmetall Denel Munition RF(Pty) Ltd has assured the City of Cape Town that the plume that followed the explosion holds no threat to the general public. All necessary precautions are being taken and the investigation will carry on at first light tomorrow,"

Due to the munitions plant being a National Key Point, the City said Rheinmetall Denel Munition would handle any further communication on the incident and that no further information was available.

Earlier, the City's Fire and Rescue Service's Theo Layne had said: "The City's Fire and Rescue Service responded to Rheinmetall Denel Munitions Factory at 15:45. On arrival, it was ascertained that an explosion had occurred and the staff was in the process of extinguishing the subsequent fire.

"Four persons are confirmed to have sustained fatal injuries and firefighters are currently carrying out search and rescue for a further six persons."

All missing people have now been accounted for, the City said this evening.