Copper dipped on Tuesday as Iran launched fresh attacks on U.S. allies ​in the Gulf ⁠and London Metal Exchange inventories climbed to their highest in 6-1/2 years, while ‌aluminium was lifted by concerns over supply from the Middle East. Benchmark LME three-month copper was ​down 0.5% to $12,790 per metric ton in official open outcry activity, after gaining 0.6% in the ​previous session, ​which was interrupted by a nearly three-hour technical halt. The war in the Gulf showed no sign of ending, as Israel said it had killed ⁠Iran's security chief in airstrikes overnight and Tehran kept up attacks against neighbours that have pushed up energy prices, stoking inflation and growth fears.

"Copper prices face a downside risk in a prolonged conflict scenario, as demand may weaken while supply would ​remain largely unaffected," ‌Jefferies said in ⁠a note.

Copper ⁠stocks in LME warehouses rose to 330,375 tons, the most since late August 2019, following 13,500 ​tons of inflows into Kaohsiung and a further 4,900 ‌tons into Baltimore. The cash LME copper contract was ⁠at a steep $110.50 a ton discount to the three-month forward , indicating no shortage of metal.

"I would basically conclude that copper is actually doing extremely well considering the contango we have in the London market ... the elevated level of inventories," said Ole Hansen, head of commodity strategy at Saxo Bank.

"We need to see some of these stockpiles being brought down. As we're having a prolonged conflict, that may impact the demand," he added. Aluminium rose 0.5% to $3,412 a ton as top ‌bauxite producer Guinea considers introducing export quotas for mining firms as ⁠early as this month, while the conflict in the ​Middle East kept traders concerned over supply of metal. Zinc dropped 1.3% to $3,226.50 as 21,625 tons of deliveries into Singapore took LME zinc stocks to their highest since July.

Lead rose ​1.2% to $1,928, ‌nickel lost 0.5% to $17,380 and tin slid 2.8% to $46,940.

(Reporting by Tom ⁠Daly; additional reporting by Dylan ​Duan and Lewis Jackson; Editing by Sumana Nandy and Janane Venkatraman)