Water has been restored to most parts of Johannesburg that were left with their taps running dry following a fire at the Rand Water Eikenhof pumping station on Monday, Johannesburg Water said on Thursday."We are currently working on restoring a small portion that is still without water and we're adding more water tankers in those areas," said Johannesburg Water communications officer Eleanor Mavimbela in a statement.Most reservoirs and towers in the areas that were affected were now fully operational, however, Helderkruin, Willropark and Roodekrans still had no water or were experiencing low pressure, he said.Water tankers have been dispatched to points including Mimosa and Steenbras streets in Helderkruin and at the Sterlig Retirement Village on Naboom Street in Wilropark.Tankers are also being driven around the three suburbs, according to the statement.Sabotage suspectedTankers would also roam around the Randburg Clinic, Medicross Randburg, Ferndale High School and the corner of Sirdar and Abington streets in Kensington B where JoJo tanks are onsite.The tankers would go to the Olivedale Hospital to refill hospital tanks too.Johannesburg City Power said it suspected that the cause of the explosion at Eikenhof was a "result of a deliberate act of sabotage".A video had emerged which proved that the fire had originated outside the transformer at the substation, City of Johannesburg Mayor Herman Mashaba said in a statement on Tuesday.WATCH: City Power suspects 'deliberate acts of sabotage' after Eikenhof substation blastMashaba said the transformer appeared to have been "maliciously damaged so that it would leak oil onto the fire"."These facts are simply not consistent with a fire originating from an electrical fault."I have requested that City Power immediately refer this matter to the City's Group Forensics and Investigation Services (GFIS) and the South African Police Service for further investigation," he said.Rand Water spokesperson Justice Mohale said on Monday that an electrical transformer belonging to City Power had exploded. City Power engineers and technicians worked throughout the night to repair the substation.