China has again tightened its pandemic restriction measures in Beijing and elsewhere as outbreaks of COVID-19 continue ahead of the Winter Olympic Games, set to begin in just over two weeks.

Children attending international schools in Beijing will be tested beginning next week, and airline travelers who had layovers will be banned from entering the city. Residents of the massive metro area are being told to travel only if they absolutely must, though they are not being guaranteed reentry if it is discovered that they visited a spot where cases are surging.

Tianjin, a city about an hour outside of Beijing will begin its third round of mass testing on Saturday morning. Residents of the manufacturing hub are already in lockdown, as are individuals in a half dozen other cities. Currently, all travel between Tianjin and Beijing has been suspended.