Flaming tensions in the Middle East Gulf have been keeping bunker suppliers in Singapore busy as an increasing number of shipping companies are opting to procure fuel in the Asian city-state rather than risk using Fujairah, the Middle East’s largest bunkering port.

Singapore has enough supply, but shipowners are having to pay a premium for bunkers.

Singapore’s prices for IFO 380 fuel, commonly known as high-sulphur fuel, rose from $373 per tonne to $500 per tonne immediately after the attacks on Frontline’s 110,000-dwt LR2 tanker Front Altair (built 2016) and...