On Friday, the Australian Financial Review reported China had notified oil refiners to halt all exports, casting doubt over at least two cargoes due to be shipped to Australia.
Since the beginning of the conflict, the price of urea, a key source of nitrogen used in agriculture, has surged by about 25%, similarly dramatic to the spike in crude oil prices.
Shipping in the crucial Strait of Hormuz, the only sea passage from the oil-rich Persian Gulf to the open ocean, has come to a virtual standstill, sparking a global oil price rise of about 10%.