WASHINGTON – Federal health officials on Thursday ordered dozens of imported foods from China held at the border as possible health risks. Most are ethnic treats, including snacks, drinks and chocolates.

It’s unusual for the Food and Drug Administration to put such a broad hold on goods from an entire country, not just a few rogue manufacturers. The order, which covers products made with milk, is a precaution to keep out foods contaminated with the industrial chemical melamine, which can cause serious kidney problems.

Under the directive, FDA inspectors at U.S. ports of entry will detain foods from China made with milk and certain ingredients derived from milk. Importers must pay to have their products tested by an independent laboratory that meets FDA standards. Only products found to be melamine-free will be allowed into the country.