Primary aluminium production rates in the Gulf region fell by 6% in March from the prior ​month, the International Aluminium Institute said on Monday, warning that the impact of the conflict in the Middle East ​will get ​worse. The IAI data gives an initial quantification of the dent to aluminium supply caused by the conflict, which has seen the region's two biggest smelters come under Iranian ⁠attack and complicated both inbound raw material and outbound metal shipments due to the closure of the Strait of Hormuz.

Daily production from the Gulf countries, which account for around 9% of global aluminium smelting capacity, fell to an average of 15,963 metric tons in March, down from 16,997 ​tons in February, ‌the IAI said ⁠in a statement.

"We ⁠do not yet have final March figures for all our members' smelters at this point, and we ​can expect the actual output to be lower still when the full ‌dataset becomes available in May," IAI Secretary General Jonathan Grant ⁠said. The Gulf data is not broken down by country. Emirates Global Aluminium, of the United Arab Emirates, and Aluminium Bahrain have both been attacked, while Qatar's Qatalum is operating at only 60% after strikes on its energy supplier.

EGA said on April 3 it could take up to one year to resume full production at its Al Taweelah smelter.

"Three of our members have announced cuts in their production following attacks on their smelters or energy infrastructure. So, we can expect the impacts of the war on aluminium production to continue to get ‌worse," Grant said.

"Reopening the Strait is essential to allow producers ⁠to restock raw materials and export finished products that have been ​largely stranded at smelters," he added. "This is now having a knock-on impact on supply-chains extending as far as Australia, which supplies alumina to some of the Gulf smelters."

Global primary aluminium output in March ​rose 0.9% year-on-year to ‌6.302 million tons, but the daily rate was down 0.3% from ⁠February, the IAI said.

(Reporting by Tom ​Daly; additional reporting by Polina Devitt; Editing by Joe Bavier and Chizu Nomiyama )