(Yicai Global) March 23 -- The three major stock indexes of China's A-share market fell sharply today as U.S. President Donald Trump signed a presidential memorandum imposing tariffs and investment restrictions on China with an annual value of up to USD60 billion. China's stock market indexes suffered the biggest drop in six weeks today.

The Shanghai Composite Index plummeted by 3.39 percent to 3,152.76 points. The Shenzhen Composite Index suffered a sharp decline of 4.02 percent at 10,439.99 points. The Growth Enterprises Market (GEM) index slumped over 5 percent to 1,726.02 points.

A total of 170 stocks dropped by the daily limit of 10 percent on the Shanghai Stock Exchange and the Shenzhen Stock Exchange and over 1,000 stocks sank over 7 percent during the afternoon session, state-run Xinhua News Agency reported, bringing the number of companies whose shares fell by 10 percent limit during today's trading to more than 400.

Shares of all sectors fell. However, stocks related to industrial internet and unicorns topped the list of hardest-hit shares, followed by those related to agricultural products processing as the Trump administration's new tariffs cover information technology, telecoms and consumer products imports from China.

The new tariffs will mostly affect China's aerospace, information and communications technology and machinery industries, said China International Capital Corp. Ltd. in a report today. In addition, industries with a relatively high trade share will also suffer a blow.

China's exports to the U.S. mainly include mechanical equipment including household appliances and electronics, which accounts for 48 percent of the total exports, miscellaneous products (12 percent), textiles (10 percent), and metal products (7 percent). The US's exports to China involve machinery and equipment, particularly capital goods (30 percent), transport equipment (20 percent), chemicals (10 percent), and plastics and rubber products (5 percent).

The U.S. exports to China amounted to USD9.8 billion in January, while its imports from China reached 45.7 billion, according to the United States Census Bureau. The U.S. trade deficit with China hit USD375.2 billion last year, data from the Bureau showed.