China's state security agency says it is cracking down on alleged smuggling of rare earths minerals that it says threaten national security, just weeks after Beijing and Washington agreed to make it easier for American firms to obtain from China those materials, which are critical for manufacturing and computer chip production.

In a report published Friday in the state-run newspaper Global Times, the Ministry of State Security said foreign "espionage and intelligence agencies" were colluding to steal rare earths-related goods by repackaging and relabeling rare metals to hide their Chinese origin.