Shares of Micron Technology, Inc. MU sharply declined in premarket trading on Monday after China announced a ban on the US company’s products.

The Cyberspace Administration of China announced on Sunday that a network security review of Micron’s products sold in China found them to have relatively serious potential network security issues.

These pose a major security risk to the supply chain of China’s critical information infrastructure and affect national security, the agency said. Also, operators involved in domestic critical information infrastructure projects have been asked to stop purchasing Micron products.

Based in Idaho, Boise, Micron sells computer memory and computer data storage, including dynamic random access memory, flash memory, and USB flash drives.

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Accordingly, shares of Micron fell 5.57% to $64.37 Benzinga Pro dates.

Other chipmakers reacted sympathetically, although there is no explicit announcement from China about their products.

Advanced Micro Devices, Inc. AMD and Nvidia Corp. NVDA, which is heavily exposed to China, fell 1.41% and 1.36%, respectively. Intel Corp. INTC fell a more modest 0.57%.

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