Eleven factory workers were injured in an explosion at one of the factories at the East London Industrial Development Zone on Tuesday evening, with the explosion heard as far away as Cove Rock.
People across East London reported hearing the loud explosion, which rattled windows and doors.
Police spokesperson Warrant Officer Hazel Mqala confirmed the explosion took place at around 21:45 on Tuesday evening.
"At this stage, it is suspected that the cause of the explosion is the chemicals that they are working with at the factory," she said.
Eleven people -- eight men and five women -- were injured and were taken to hospital for medical attention.
"Firefighters were also summoned to extinguish the fire and the factory is currently closed."
Mqala said an inquiry would be opened.
In a statement on Tuesday night, the ELIDZ confirmed that there had been an incident within one of their enterprises in the zone.
"At this point we have not yet ascertained the cause or the extent of the damage. Emergency Services and our technical team are on site. There were no major injuries reported," the ELIDZ said.
Feltex Automotive Trim is a "leading supplier of automotive acoustic comfort and trim components".
The company's automotive division comprises seven business units that supply products directly and indirectly to the South African vehicle manufacturers, with its head office in Durban.
"This division is now one of South Africa's largest automotive component manufacturers with manufacturing facilities situated in Durban, Rosslyn (Pretoria), Ga-Rankuwa (Pretoria), Port Elizabeth and East London, in close proximity to the assembly plants to facilitate 'just in time' and 'just in sequence' supply," the company states.