Middle Eastern oil exports have rebounded to their highest levels since the Iran war began in February, as Gulf producers find ways around the Iranian blockade of the Strait of Hormuz. Shipments from Saudi Arabia, the United Arab Emirates, Qatar, Bahrain, Kuwait and Iraq have averaged 15.5mn barrels a day in September, the highest level of the war and more than 80 per cent of the average in the 12 months before the conflict began, according to data provider Kpler.

The recovery in exports threatens to diminish Tehran’s leverage in negotiations with the US for a peace agreement. The increased shipments were “primarily a reflection of Gulf export systems gradually getting back on their feet after months of disruption”, said Anshika Prajapati, an analyst at maritime consultancy Drewry. The shipments appear to have done little to contain oil prices, however, with Brent crude rising from about $90 a barrel at the end of August to more than $100 today.

Saudi Arabia, the world’s biggest exporter, has sought to bypass the strait by sending oil through its East-West pipeline. It was forced to halt flows through the pipeline after an attack on September 10 and increase its exports through the strait. Saudi Arabia’s total oil exports through all routes more than doubled in September to 6.9mn barrels a day, according to preliminary data compiled by Kpler. Flows from the UAE and Bahrain have also risen.

Shuttle services and ship-to-ship transfers have continued despite attacks on shipping in the strait. UK Maritime Trade Operations has reported four attacks in the past week, including one tanker that caught fire in the strait overnight on Monday. The vessel was the Kuwaiti supertanker Al Funtas, which has sailed multiple times through the waterway in the past three months.