This photo taken on January 15, 2021, shows people in protective suits spraying disinfectant on a street at Gaocheng district, which was declared a high-risk area for Covid-19 in Shijiazhuang, in northern China's Hebei province. Photo: AFP/STR

Nearly three million people were put under lockdown in China Monday after a surge in coronavirus cases linked to a traveling salesman in the country’s northeast.

While China has largely brought the virus under control, a sharp rise in cases in the past few weeks has prompted fresh lockdowns, travel restrictions and multiple rounds of mass testing. 

Monday saw three million residents of two cities in northeastern Jilin province placed under new measures, as China reported 109 new infections. 

More than 19 million people across China’s northeast are now barred from leaving their homes, and in some cases can only apply for permission to go grocery shopping once every three days.

Authorities have traced more than 100 infections in Jilin province to an asymptomatic traveling salesman from neighboring Heilongjiang, where authorities last week declared a state of emergency.

The salesman had traveled to two different cities, now locked-down, and given healthcare workshops to middle-aged and elderly residents, according to local officials.

An investigation has been launched into the health care centers that hosted the workshops to determine whether their operations constitute illegal business activities. 

Health care workshops that sometimes market products claiming to boost “longevity” have been accused of preying on vulnerable groups in China, particularly the elderly.

The People’s Daily, a state-run newspaper, ran a commentary on Monday lambasting the workshops as “risking lives for money, under the guise of caring about the health of the elderly.”

Lockdowns were also extended across other areas of China’s northeast over the weekend, including one district of Harbin, now hosting a popular ice sculpture festival that is usually a big draw for tourists.

But local authorities partially lifted lockdowns in two cities in Hebei province outside Beijing – which has accounted for the majority of cases in recent weeks – though some 12.5 million are still being told to stay home.

More than 20,000 residents of villages in the area have been sent into quarantine in a centralized location, state media reported last week.