Because of certain disruptions of supply, O.R. Tambo International Airport in Johannesburg currently has only 3.1 days’ worth of jet fuel stock available and not the the usual five days’ worth of fuel stock. Fuel is still being delivered daily, but simply not in the normal quantities.
The management of the airport had discussions with the relevant role players, in particular the fuel suppliers, and, according to the officials, everything possible is being done to ensure that the fuel supply situation normalises as soon as possible.
[I couldn't find any info why there are jet fuel supply constraints at ORTIA - do you know the reason?]