The Nikkei index on the Tokyo stock market opened lower this morning, following the direction of Wall Street which closed sharply down overnight, amid concerns that the Middle East crisis could intensify after reports that US President Donald Trump is considering further strikes on Iran. The Nikkei opened at 65,584.25 points, down 838.35 points or 1.26 percent, and in the first 15 minutes of trading the index fell 1,699.49 points or 2.56 percent to touch 64,723.11 points. The biggest decliners were air transport, non-ferrous metals, and electrical appliance stocks.