South African inflation picked up more sharply than expected in June, bolstering expectations that the central bank will deliver a second consecutive interest rate hike on Thursday.

Annual headline consumer inflation accelerated to a two-year high of 5.0% in June from 4.5% in May, data from Statistics South Africa showed on Wednesday. Economists polled by Reuters had expected a reading of 4.7%.

The transport category was the largest contributor to both the annual and monthly rises in the Consumer Price Index, as the Iran war sent fuel prices sharply higher.

Annual core inflation, which strips out volatile items like food and energy, came in at 4.1% in June, also above economists' forecast for a reading of 3.9%.

RATE HIKE NOW LOOKS MORE CERTAIN