METALS-Copper hits 3-week low on stronger dollar as Middle East war intensifies

May 5 (Reuters) - London copper eased to a three-week low on Tuesday, pressured by a firmer dollar as tensions in the Middle East kept concerns over a slowdown in global economic growth simmering.

Benchmark three-month copper CMCU3 on the London Metal Exchange fell 0.7% to $12,907 per metric ton by 0530 GMT, having hit earlier in the day its lowest level since April 13.

Trading activity was muted, with the Shanghai Futures Exchange closed for the Labour Day holiday. Trading will resume on Wednesday.

The U.S. and Iran launched new attacks in the Gulf on Monday as they wrestled for control over the Strait of Hormuz with duelling maritime blockades.

It came not long after U.S. President Donald Trump launched a new effort to get stranded tankers and other ships through the vital energy-trade chokepoint.

The U.S. said it had destroyed six small Iranian military boats, while an oil port in the United Arab Emirates, which hosts a large U.S. military base, was set ablaze by Iranian missiles.

"It seems to be less of an individual sector (theme) and more of an increasingly macro focus on essentially what is now an indefinite bottleneck in Hormuz and its inflationary consequences," said Ilya Spivak, head of global macro at Tastylive, adding that a firmer dollar was further pressuring copper prices.

The U.S. dollar rose on safe-haven demand as Middle East tensions continued to weigh on markets. USD/

Stocks in Asia slid while oil prices eased but remained well above $100 a barrel, as the U.S. and Iran continued to work towards a truce while trading blows over the strait. MKTS/GLOB O/R

Among other LME metals, aluminium CMAL3 fell 0.7%, nickel CMNI3 slipped 0.3%, lead CMPB3 was up 0.1%, tin CMSN3 lost 0.8%, and zinc CMZN3 shed 0.6%.