According to Atlas.News
(Things are still a little unclear about this development) Chinese authorities have reportedly quarantined over 14,000 travelers in the busy Shanghai Pudong airport after a breakout of positive COVID-19 cases among several workers. Tensions boiled over as crowds tried to force their way out of the airport. I’ve seen some reports that they are attempting to test every person within the airport, but this is unconfirmed.
This story will be updated as more information comes in.