China reported 26 new cases of coronavirus Saturday, as a spread of cases linked to domestic vacation travel continued to be felt around the country and officials ordered mass testing and lockdowns in some areas.

New cases were concentrated in the northwestern provinces of Inner Mongolia, Gansu and Ningxia. Four cases were also reported in Beijing, the capital.

China has imposed a strict regimen to control the spread of the coronavirus that first emerged in the city of Wuhan in late 2019. Its government has not reported any large or significant outbreaks this year.

The new domestic case numbers were down slightly from Friday, when 38 were reported, the highest since mid-September.

Several of the most recent cases have been linked to a couple from Shanghai who traveled to Shaanxi, Gansu and Inner Mongolia. A subsequent outbreak in the Changping district of Beijing was traced to a group of Beijing residents who had traveled to Inner Mongolia and back by car.

This week, Beijing has sealed off parts of the Changping district for large-scale testing, closed some community centers and asked residents not to leave the city unless necessary.

Five cities in Gansu shut down tourist attractions, theaters and other public places and imposed restrictions on movement to prevent further spread, the state-run Lanzhou Evening News reported Saturday.