By Pratima Desai
March 30 (Reuters) - Aluminium prices surged to four-year highs on Monday as Iranian airstrikes on two major Middle East producers over the weekend raised the risk of a prolonged supply shock.
Benchmark aluminium CMAL3 on the London Metal Exchange traded 3.9% higher at $3,424.5 a metric ton in official rings. Prices of the metal used in the transport, construction and packaging industries touched $3,492 earlier in the session.
The U.S.-Israeli war on Iran and resulting closure of the Strait of Hormuz has already restricted shipments of aluminium to export markets in the United States and Europe.
Aluminium Bahrain ALBH.BH, which runs the world's largest single-site smelter, said it was assessing the damage from the Iranian strikes. Emirates Global Aluminium, meanwhile, said its plant sustained "significant damage".
Alba said this month that it was shutting smelting lines representing 19% of its capacity.
"Iran's strikes on Middle Eastern aluminium plants are threatening to send a fragile market into crisis, raising the prospect of record prices," Britannia Global Markets said.
"The conflict's impact is being amplified because constraints on production elsewhere have eroded global inventories, leaving the market with little buffer against shocks."
Aluminium prices hit a record $4,073.50 a ton in March 2022 after the invasion of Ukraine by Russia, a top producer of the metal.
Stocks of aluminium in LME-approved warehouses have dropped more than 60% since last May to 418,675 tons.
Concerns about severe shortages have pushed the premium for cash metal over the three-month contract to more than $60 a ton, its highest since 2007 .
Industrial metals overall were supported by signs of stronger demand in top consumer China.
Analysts expect Chinese factory activity to have expanded in March, ending a two-month contraction, though supply chain shocks from the Iran war cloud the outlook.
Copper CMCU3 was up 0.2% at $12,220 a ton, zinc CMZN3 gained 1.4% to $3,158, lead firmed 0.7% to $1,910.5 and tin CMSN3 climbed 2.2% to $46,800 while nickel advanced 0.4% to $17,260.