China is striving to contain a fresh COVID-19 outbreak that has spread to nearly half of the country, with police in the capital meting out punishments to those who refuse to comply with curbs.

More than 200 people have been diagnosed since the latest flare-up began 10 days ago, as tourists visiting scenic spots in the northwestern part of the country contracted the virus and spread it further once they returned home. A total of 34 infections, including 11 people without any symptoms, were reported on Thursday.

The virus has spread to 14 out of 31 provinces across the Chinese mainland. The broadest outbreak since COVID-19 first emerged in Wuhan occurred this past August, when infections were found in 16 provinces.

The outbreak expanded to the western province of Sichuan on Wednesday. Four infections were found in the northernmost city of Heihe on the Russian border, which triggered a lockdown of its 1.58 million people. It’s the third city in China to confine people to their homes during the current outbreak. Inner Mongolia’s Ejin county and Lanzhou, the capital of northwestern Gansu province, were also placed under lockdown after more infections emerged.

Cases in the closely guarded Chinese capital, Beijing, continue to grow, as local police move to discipline people who flout curbs like mask requirements and travel restrictions introduced to prevent transmission of the virus. Municipal police said they have punished 13 people and opened 19 criminal investigations for actions that impeded their efforts to snuff out COVID-19, in line with China’s zero-tolerance elimination strategy.

While authorities acknowledge that most citizens comply with restrictions put in place to control the virus, the outbreak in the capital has been fanned in large part by people ignoring restrictions. That prompted a stern warning at a government briefing on Wednesday that local police will actively seek out and punish misbehavior.

Several people have been detained by Beijing police for not being forthcoming about their travel history to high-risk places, for refusing to wear masks or scan their health codes as required, or for hurting workers that urged them to comply, according to Pan Xuhong, a spokesman for the Beijing Public Security Bureau.

China has been successful at wiping out the virus for long stretches because of the extensive powers afforded to officials to do everything from mass-test entire cities to restrict travel within the country. Residents have been willing to go along with these measures, but with the pandemic set to enter its second year and China still closed off from the rest of the world, levels of complacency and even resistance may rise. The country is the last to still be wedded to a COVID Zero strategy of keeping borders closed and seeking to eliminate all cases.

A majority of the more than 20 infections found in Beijing can be traced back to a couple who returned from a virus hot spot in northwestern China earlier in the month. They spread the virus to friends they invited over to their home to play mahjong, even though they had persistent fevers. Eventually more than 1,500 people were exposed as the couple visited shops, restaurants and banks in their neighborhood.