By David Stanway and Yawen Chen

SHANGHAI/BEIJING (Reuters) – Mainland China reported the biggest daily rise in coronavirus cases since Feb. 22 on Sunday as more infections emerged among prison inmates in the epicenter of the outbreak, but officials emphasized the overall situation continues to improve.

A total of 573 news infections were reported on Feb. 29, compared with 427 a day earlier, according to the National Health Commission. Some 565 of these were in Wuhan, where the outbreak emerged late last year.

The official China News wire service reported that 233 of the Wuhan cases were reported from the city’s prison system.

The 35 new deaths reported on Saturday were the second lowest daily total in February and down from 47 the previous day, however. There were also only three new cases outside Hubei province, of which Wuhan is the capital, the lowest since the commission began tracking daily cases on Jan. 20.

A total of 2,870 people have died from the outbreak in mainland China and 79,824 have been infected by the virus.

Chinese officials have reiterated that efforts to curb the outbreak are achieving positive results, with the daily new cases being reported trending lower in recent weeks.

To cushion the economic impact of the epidemic, China has ordered districts to be classified into “high-risk”, “medium-risk” and “low-risk”, with the latter expected to end traffic curbs and let everyone resume work.

On Saturday, Hubei said 11 of its 103 counties had reported no new cases for at least 14 days, meeting “low-risk” criteria. But as many as 58 of its counties are still deemed “high-risk”.

China needs to take a long-term view of the outbreak and plug loopholes in its laws and emergency response mechanisms, President Xi Jinping said in speeches published in the Communist Party’s theoretical journal, Qiushi (Seeking Truth), on Sunday.

China must set up an emergency reserve and supply system to ensure vital materials are deployed at critical times, he added.

As coronavirus cases spread overseas, Beijing is starting to raise its guard to avoid a resurgence of the outbreak through travelers from other countries.

More than 50 countries have reported cases with Mexico and San Marino the latest additions. In a bulletin issued Saturday, the World Health Organization said there were 6,009 cases outside China, an increase of 1,318 from the previous day.

China has refrained from blanket travel bans, but some local governments, such as in Beijing, have ordered self-quarantine for travelers from countries where the virus has spread.

Beijing on Sunday reported two new cases: both are Chinese nationals who recently returned from Iran, where the coronavirus cases have multiplied quickly.

China will take steps to bring back citizens from high-risk countries if necessary, foreign ministry official Cui Aimin told reporters on Sunday. He said Beijing has arranged 10 flights to bring home 1,314 so far, but did not name any countries.

(Reporting by David Stanway in Shanghai, Hallie Gu and Yawen Chen in Beijing; Writing by Se Young Lee; Editing by Mark Heinrich)