People in China are resuming travel ahead of the Lunar New Year despite worries about infections after Beijing dropped COVID-19 curbs.
Air passenger volumes in China have recovered to 63 per cent of 2019 levels since the annual travel season began.
The rapid business recovery is challenging airlines' ability to ensure safety, and great attention to pandemic-related risks is needed, Civil Aviation Administration of China head Song Zhiyong said.
The industry needs to "fully understand the special nature, and complexity of the spring festival migration in 2023", Song said in a statement on Friday.
Since the January 7 start of the annual migration, as Chinese return to their home towns in preparation for holidays that begin on January 21, flight passenger numbers are at 63 per cent of the 2019 figure before the pandemic, the aviation regulator said.
China re-opened its borders on January 8 after abruptly abandoning a strict anti-virus regime of frequent testing, travel curbs and mass lockdowns that fuelled historic nationwide protests in late November.
The transport ministry has predicted passenger traffic volumes to jump 99.5 per cent on the previous year during the festival migration, which continues until February 15, or recover to 70.3 per cent of 2019 levels.
In the gambling hub of Macau, Friday's 46,000 daily inbound travellers were the highest number since COVID-19 emerged in early 2020, the majority from the mainland, the city government said.
It expects a spring festival boom in tourism.
The holiday week is also a key time for new movie releases in China.
Cinema box office receipts are on track to generate revenue of as much as 10 billion yuan ($A2.1 billion) during the spring festival period, a brokerage has forecast.
Cinema visitor numbers slumped after COVID worsened, bringing spring lockdowns last year in major cities such as commercial hub Shanghai.
The revival in activity is expected to boost revenues as seven new Chinese films, including the highly-anticipated The Wandering Earth 2, screen during the festival.
However, infections are expected to surge in rural areas as hundreds of millions return home from big cities.
That fear is reflected in a scramble for oxygen-generating equipment, as most products of top-selling brands are sold out on e-commerce platforms such as JD.com, according to Reuters checks and buyers' online comments.
One firm, Jiangsu Yuyue Medical Equipment & Supply Co is marshalling all possible resources to respond to customer needs, it assured investors on an online platform recently.
In addition, surging demand for health checks on those who have recovered from COVID is boosting hospital demand for CT scanning equipment, the China Securities Journal said.
This week, the World Health Organisation warned of risks stemming from holiday travel.
One Chinese expert has warned the worst of the outbreak has not yet passed, media outlet Caixin said this week.
"Our priority focus has been on the large cities. It is time to focus on rural areas," it quoted Zeng Guang, the former chief epidemiologist at the Chinese Center for Disease Control and Prevention, as saying.
Many in the countryside, where medical facilities are relatively poor, were being left behind including the elderly, the sick and the disabled, he said.