World shares have declined after stocks slipped on Wall Street and as a bond market sell-off deepens. South Korea's Kospi sank 4% and U.S. futures also fell. The yield on the 10-year U.S. Treasury rose to around 4.8%, as elevated energy prices and inflation worries stemming from the Iran war cloud prospects. On Tuesday, Wall Street's S&P 500 slipped 0.7%. The Dow Jones Industrial Average dropped 0.8%, and the tech-heavy Nasdaq composite fell 1%. Oil prices edged higher after the U.S. launched another round of military strikes on Iran and Iran responded by firing missiles and drones across the region.