MANILA, April 19 (Reuters) - Aluminium prices surged as much as 5 percent to their highest level in almost seven years on Thursday amid enduring concerns over strained global supply following U.S. sanctions on major Russian producer Rusal, with similar worries also spurring nickel. Three-month aluminium on the London Metal Exchange climbed as far as $2,664.50 a tonne, its loftiest since August 2011, and was trading at $2,626.50 by 0521 GMT, up 3.5 percent. The metal has risen by nearly a third since the United States announced sanctions against UC Rusal, the world's No. 2 aluminium producer, on April 6. Analysts say worries that the sanctions could hit Russia's Norilsk Nickel, the world's second-biggest nickel producer, had lit the fire under prices of the metal used to make stainless steel. "Pretty clearly there is a lot of smoke. And pretty clearly the U.S. has Russia in its sights for a number of reasons known to them," said UBS analyst Lachlan Shaw. "A logical extension would be if you were to broaden sanctions, then Norilsk would fall under that remit." LME nickel rallied as much as 3.6 percent to $15,825 a tonne, just below Wednesday's peak of $15,875 - the highest since December 2014 - when the metal soared more than 7 percent. "Unlike aluminium, which saw explicit sanctions against Rusal, there have been no explicit sanctions against nickel producers," Commonwealth Bank of Australia analyst Vivek Dhar said in a note. "However, markets are still concerned Norilsk Nickel, which is linked with both Rusal and sanctioned oligarch Oleg Deripaska, could eventually face sanctions." SHANGHAI NICKEL: The most-traded nickel on the Shanghai Futures Exchange rose as much as 5.9 percent to 109,790 yuan ($17,526) a tonne, its strongest level since June 2015. It was last up 3.1 percent at 106,920 yuan. SHANGHAI METALS: Aluminium and zinc prices in Shanghai also raced higher. Shanghai aluminium rose 3.1 percent to 15,340 yuan per tonne and zinc climbed 2.6 percent to 24,460 yuan. U.S. ALUMINIUM: Aluminium prices in the United States have soared and are expected to diverge from those traded on the LME after the U.S. Treasury Department imposed sanctions on Rusal. NICKEL DEFICIT: The global nickel market deficit narrowed to 2,500 tonnes in February from a revised deficit of 15,800 tonnes in the previous month, the International Nickel Study Group said. BHP IRON ORE: BHP Billiton Ltd cut its 2018 fiscal year iron ore output guidance, citing issues in its railroad car unloading system, after reporting an 8 percent rise in third-quarter iron ore production. CHINA BAN: China will ban the imports of 16 more scrap metal and chemical waste products from the end of this year, the environment ministry said.