China's outbound shipments of rare earths in May jumped 23% on the month to their highest in a year, though Beijing's export curbs on some of the critical minerals halted some overseas sales, with shortages rippling through global manufacturing.

China has stopped almost all shipments of critical minerals that are needed for cars, robots, wind turbines, jet fighters and other technologies.

Chinese exports of rare earths—17 key minerals at the heart of trade tensions with Washington—rose 23% in May compared to the previous month, customs data showed Monday. May shipments totaled 5,865 tons—still below last year’s level—but the monthly surge lifted year-to-date exports by 2.