A number of flights were delayed at Johannesburg international airport on Sunday after an attempted cable theft left planes unable to refuel, an airport official said.
Three power cables were "severely damaged" in the attempted robbery just outside the perimeter of OR Tambo Airport, Airports Company South Africa (ACSA) spokeswoman Unathi Batyashe-Fillis was quoted as saying by Sapa news agency.
The damage had "affected the fuel pipeline's ability to transmit fuel" to aircraft, she said in a separate statement.
Police were investigating the incident and technicians were racing to restore power to the cables by late afternoon, the spokeswoman told Sapa.
"Once that is done we can then start operations as soon as possible," she was quoted as saying.
She added that around 20 flights, mainly local ones, were waiting to be cleared for take off.
The theft of metal cables to be flogged for money is widespread in South Africa, costing the country about five billion rand ($505 million, 372 million euros) a year, according to police estimates.
In May last year, harsher sentences were introduced for the crime, with buyers of stolen cables facing the same penalties as the thieves themselves, including up to 10 years in jail for stealing copper cables.
In January, more than 200 people were injured in a train crash near the capital Pretoria caused by the theft of cables used for signalling.