China's exports of two critical minerals used in weapons, telecommunications and solar cells have plunged over the past three months amid a crackdown on smuggling and transshipment that has involved China's top spy agency.

China’s exports of rare-earth magnets increased nearly threefold in June from the previous month, after the country lifted some export controls on the critical industrial inputs following a deal with the U.

China's Ministry of State Security says it is cracking down on alleged smuggling of rare earths materials that it says threaten national security.