The Globe and Mail reports in its Wednesday edition that companies caught out by China's decision to restrict exports of two metals widely used in semiconductors and electric vehicles were racing to secure supplies on Tuesday as some industry suppliers worried that curbs on rare earth exports could follow. A Reuters dispatch to The Globe says that Monday's abrupt announcement of controls from Aug. 1 on exports of some gallium and germanium products has worsened a trade war with the United States and could potentially cause more disruption to global supply chains. Analysts saw the move, which the Chinese Commerce Ministry said was to protect national security, as a response to escalating efforts by Washington to curb China's technological advances. It came on the eve of U.S. Independence Day and just before U.S. Secretary of Treasury Janet Yellen visits Beijing. "China has hit the American trade restrictions where it hurts," said Peter Arkell, chairman of the Global Mining Association of China. The European Commission expressed concern. Shares in Teck Resources Ltd., North America's biggest germanium producer, briefly jumped more than 1 per cent in early trading. At closing, they were up 0.11 per cent.