The U.S. ambassador to China says Beijing is interrogating and intimidating its citizens who attend U.S.-organized events in China, ramping up restrictions on the embassy's social-media posts and whipping up anti-American sentiment.

The U.S. ambassador to China says Beijing is interrogating and intimidating its citizens who attend U.S.-organized events in China, ramping up restrictions on the embassy’s social-media posts and whipping up anti-American sentiment.