At least eight people were killed Monday in an explosion at a munitions depot in Somerset West, near Cape Town, on Monday has risen to eight, Theo Layne, a fire and rescue spokesman said.

"I can confirm that eight people are dead," he said, adding that the cause of the blast was not known.

The explosion took place in the afternoon at a factory belonging to Rheinmetall Denel Munition in the town of Somerset West, about 45 kilometers outside of Cape Town, Layne said.

Firefighters were searching for at least another two workers, according to Layne.

The cause of the explosion, which occurred around 1300 GMT on Monday, was still unknown, the spokesman said.