Lockdown measures were being imposed in a northern Chinese province where coronavirus cases more than doubled in the region near Beijing that’s due to host some events in next year’s Winter Olympics.

Rail, air and highway connections to the Hebei capital of Shijiazhuang, a city of at least 10 million people, have been suspended and prevention and control measured tightened over urban communities and villages in the area. Classes have been suspended and school dormitories isolated.

The National Health Commission on Thursday announced 51 new cases had been confirmed in Hebei province, bringing the total to 90 since Sunday. Most have been in Shijiazhuang, although cases have also been recorded in the city of Xingtai.

Hebei is adjacent to Beijing, the host city of the 2022 Games, and some of the Olympic events are scheduled to be held in Shijiazhuang.

Authorities have also imposed similarly tight measures in the cities of Shenyang and Dalian in Liaoning province just to the north.

Wary of a new wave of infections, China is discouraging travel over next month’s Lunar New Year holiday and beginning school holidays a week early.

The increase in cases comes as China and the World Health Organization are negotiating terms for a visit by WHO investigators looking into the origins of the coronavirus, which was first detected in the central city of Wuhan in late 2019.

WHO Director-General Tedros Adhanom Ghebreyesus said Tuesday he was disappointed at the lack of permission for the experts to travel to Wuhan, but Chinese Foreign Ministry spokesperson Hua Chunying said China’s disease experts were currently busy with multiple small-scale clusters and outbreaks reported in the past couple of weeks.

“To ensure that the work of the global experts group in China is successful, we need to carry out the necessary procedures and relevant concrete plans. Currently both sides are still in negotiations on this,” Hua told reporters at a briefing on Wednesday.

China has reported a total of 87,278 cases of COVID-19 and 4,634 deaths.

(AP)