The Department of Correctional Services (DCS) has launched an investigation after a fire broke out in a prison cell at Leeuwkop Correctional Centre in Johannesburg on Tuesday.According to the department, officials at the prison managed to contain and extinguish the blaze before it could spread to neighbouring cells. "No injuries were reported as officials reacted with the necessary urgency to put out the fire when it flared up," DCS spokesperson Singabakho Nxumalo said. Nxumalo confirmed that the cause of the fire, which is currently unknown, will form part of the probe. READ | Prisoner activist accused of 'instigating revolt' after furore at prison in PretoriaDaily operations have resumed following the incident, Nxumalo said. Nxumalo told News24 there were no signs of rioting at the prison and that the fire was not connected to calls by a prisoner activist who had called for indefinite passive resistance, such as passive hunger strikes, disobedience and nudity. News24 reported on Monday that DCS is engaging with law enforcement agencies to act against Golden Miles Bhudu for "instigating inmates to revolt against the State".On Sunday, City Press reported that South African Prisoners Organisation for Human Rights (SAPOHR) CEO Bhudu demanded that DCS announce a strategy on how it would alleviate the chronic overcrowding and save the lives of inmates facing the threat of Covid-19. Failure to provide answers would lead to resistance. Nxumalo called Bhudu's efforts to mobilise irresponsible and reckless."There is no need for such. DCS is currently engaging with relevant law enforcement agencies to take necessary action," Nxumalo said.According to DCS, following Bhudu's call, inmates at the Baviaanspoort Medium Correctional Centre in Pretoria became disruptive, with one prisoner lying on his back and refusing to move into his cell on Monday.