Two Tibetans have died from a pneumonic plague spread by mice and other rodents in a southern Tibetan county, according to local media, with Chinese authorities now ordering county residents to stay at home. The two victims died in September in Lhoka city, Tsona county, Lhoka prefecture, a source in the region told RFA, adding that neither has been publicly identified.

“Moreover, people are not allowed to discuss it,” According to the source, who requested anonymity in order to speak freely. “But we have learned that the two individuals had been helping someone else showing symptoms of the plague. One of them died at a hospital in Tsona county,” the source added.

According to RFA, a strict lockdown is now in effect in Tsona, with county residents being told not to leave their homes. “And authorities are warning people not to talk openly about this issue, saying they will be charged with spreading rumors if they are caught.”

CNN reported that the region, which is home to 22 million people, many of whom are ethnic minorities, reported 38 new asymptomatic Covid cases on Tuesday. It was enough to worry officials, with Xinjiang Vice Chairman Liu Sushe vowing to take action “strengthen the control of cross-regional personnel and insist that people do not leave the region unless it is necessary”.

Liu went on to say that Xinjiang will beef up security at airports, train stations, and checkpoints to prevent the virus from spreading to other parts of the country. Until further notice, all outbound trains, interprovincial buses, and most flights will be suspended.

According to data from flight tracking company Variflight, 97% of departing flights and 95% of arriving flights were canceled on Wednesday at the airport in Urumqi, the regional capital. Meanwhile, all flights leaving Kashgar, a southern oasis town with Xinjiang’s second-largest airport, were canceled, with the exception of two to Urumqi, according to CNN.

“The current round of Covid-19 outbreak is the fastest spreading, most widespread, most infectious, and most difficult to control public health emergency in the history of Xinjiang,” Liu said.

Xinjiang has reported a total of 5,790 infections since July 30. Xinjiang, according to Liu, will “create a favorable environment” for the success of the 20th Party Congress, a meeting of the party elite later this month at which Xi Jinping is expected to be appointed to a third term in power, cementing his status as the most powerful Chinese leader in decades.

The run-up to the congress, the most important event on the Chinese political calendar, is especially sensitive, with authorities working across the country to smooth the way and contain any potential hiccups – such as an untimely Covid outbreak, according to CNN.