STORY: The uptick in cases was smaller than numbers detected in the cities of Guangzhou and Zhengzhou, but enough to spark a new burst of PCR tests for many of its residents and a lockdown of more buildings and neighborhoods.

Nationwide, new locally transmitted infections climbed to 7,475 on November 7, according to China's health authority, up from 5,496 the day before and the highest since May 1. Guangzhou accounted for nearly a third of the new infections.

The increase was modest by global standards but significant for China, where outbreaks are quickly tackled when they surface.

The sharp rebound will test China's ability to keep its COVID measures surgical and targeted, and challenge the expectations of investors that the world's second-largest economy could soon reopen its borders or even back off from its zero-tolerance approach.