Yangzhou, Jiangsu province, has taken stricter measures to contain its COVID-19 outbreak after recording 32 new locally transmitted confirmed cases on Tuesday.

The city, with a population of more than 4.5 million people, has imposed a partial lockdown in all its downtown communities, with only one person per household allowed to go grocery shopping. It has also started disinfecting hundreds of mahjong lounges, all of which have been closed.

Among the 126 cases reported in the city by Tuesday, many were mahjong enthusiasts aged 60 or above who were infected when playing mahjong in densely populated lounges with poor ventilation, the Jiangsu Provincial Health Commission said.

Yangzhou has quarantined more than 3,000 people living in the same community as its "patient zero", who arrived in the city from Nanjing, the provincial capital, and has been detained on suspicion of impeding the prevention of infectious diseases.

The 64-year-old woman, surnamed Mao, has been dubbed "the person who destroyed a city" by some internet users.

Yangzhou police said on Tuesday that not only did she ignore all of Nanjing's virus containment measures to travel to Yangzhou, but she also refused to report her travel history upon arrival. She visited many of the city's restaurants, farm product markets and mahjong lounges frequently, and refused to cooperate with police when she was detained.

"Mao may face up to three years in prison," said Lan Tianbin, a lawyer with Dongheng Law Firm in Nanjing. "She could also be sentenced to three to seven years behind bars if her behavior causes severe consequences, such as many deaths.

"Mao is receiving treatment in hospital but will be transferred to a detention center when her health permits. Chinese law only allows people age 75 and above to be eligible for reduced sentences following comprehensive consideration of the nature, circumstances and consequences of the crimes, which Mao doesn't fit."

Mao's behavior has angered many people in Yangzhou.

"She disturbed the life of millions of people and put other people's lives in danger," said Luo Qiu, who lives in Yangzhou's Hanjiang district.

Four of the infected people in Yangzhou are in serious condition and two others are in critical condition. Some patients are aged 80 and above.

"Thousands of people had to work while drenched in sweat on hot days to disinfect the environment, take swab samples and deliver supplies to many communities due to her irresponsibility," Luo said.

Nanjing reported three locally transmitted cases on Tuesday, taking the total since July 20 to 223.

The Chinese mainland reported 71 new locally transmitted cases on Tuesday, the National Health Commission said on Wednesday. Thirty-five were in Jiangsu, 15 in Hunan, nine in Hubei, six in Shandong, three in Yunnan, two in Henan and one in Fujian, it said.