A province in northwest China heavily dependent on tourism closed all tourist sites on Monday after discovering new cases of COVID-19.
Gansu Province lies along the ancient Silk Road and is famous for Dunhuang Caves filled with Buddhist images and other religious sites.
The National Health Commission said 35 new cases of local transmission had been detected in the past 24 hours, including four in Gansu.
Another 19 cases were found in the Inner Mongolia region, with others spread across several provinces and cities. Residents of parts of Inner Mongolia have been ordered to stay inside.
Although it has largely eliminated cases of local infection, China maintains a policy of zero tolerance towards the pandemic, characterized by lockdowns, quarantines and mandatory testing for the virus.
Of particular concern is the spread of the delta variant by travelers and tour groups ahead of the Beijing Winter Olympics in February. Overseas spectators are already prohibited, and participants will have to stay in a bubble between them and outsiders.
Authorities in the capital said on Sunday that people arriving from places with recent infections should present a negative virus test result and provide regular health reports.