Residents of the Chinese capital were also advised not to leave the city unless necessary, although regular transport services out of the city continued as normal.
China reported 39 new cases on Monday, bringing the tally from the latest Delta variant-linked outbreak to more than 100 cases over the past week.
The numbers are extremely low compared with most other places in the world, but China has pursued a zero-case strategy throughout the pandemic and authorities are determined to stamp out the latest outbreak with the Winter Olympics just over 100 days away.
Several housing compounds in the capital have been locked down, and organisers on Sunday indefinitely postponed a marathon at which 30,000 runners were expected.
And at a Sunday press briefing, Xu Hejian, vice minister of Beijing’s publicity department, advised people against large gatherings and “unnecessary” travel out of the capital.
Those entering the city from areas with Covid cases must show a negative test, officials said.
Health officials have warned that more infections may emerge as testing is ramped up in the coming days to fight the outbreak, which has been linked to a group of domestic tourists that travelled across China.
Authorities on Sunday suspended inter-provincial tour groups in five areas where cases have been detected, including Beijing.
Northern China has accounted for the majority of cases, with mass testing under way in eleven provinces.
A stay-at-home lockdown started Monday for around 35,000 people — including tourists — in Inner Mongolia region’s Ejin county.
Some cities, including Gansu’s provincial capital Lanzhou, and parts of Inner Mongolia have suspended bus and taxi services and closed tourist sites.
In the central city of Wuhan — where the coronavirus was first identified in late 2019 — organisers abruptly cancelled another marathon Sunday that was expected to draw 26,000 participants.