Chinese cities battle Covid as Winter Olympics loom

Here's a rundown of the measures in place in key areas of the world's most populous nation. Tianjin is home to China's largest domestic Omicron cluster to date, with almost 300 local cases reported since the highly transmissible variant was first discovered over a week ago. Officials have not yet identified the source of the outbreak, as the city completed a third round of mass testing on its 14 million residents last week. Authorities have stopped short of ordering a complete lockdown of the city, an important industrial manufacturing and port hub. Last week, carmakers Toyota and Volkswagen shut down…