10 ballet dancers leaned on a horizontal bar that straddled the balance during training, and gracefully stretched their limbs, standing on the toes of the rhythms of classical piano music.

It could be a day like all the days in the Shanghai Ballet Ensemble, one of the finest Chinese dance bands, founded in 1979 with the exception of one thing that all those in the hall were wearing masks due to the outbreak of the Coruna virus.

The band members returned this week to their work after the Lunar New Year holiday (Spring Festival), which was extended due to the virus, and some of them had difficulty breathing during training due to the masks.

"This is the first time in my life that I have been training with a muzzle ... I think I need to improve my physical fitness because after a few movements I found myself breathing hard," said Wu Hu Xing, the group's main dancer.

Wu, 33, said he could train normally for one hour at a time, but he had difficulty breathing after only 20 minutes of training in a muzzle.

Shanghai, like other parts of China, is urging residents to stay at home due to the outbreak that has killed more than 2,200 people and infected more than 75,000 on the Chinese mainland.

But Chen Li Li, director of the Shanghai Ballet Ensemble, says the 14-day self-quarantine that city authorities obliged residents to implement might have caused dancers to fall behind training dates in preparation for April's performances if they were to take place.

The band also faces a shortage in the number due to the inability of some dancers to return from their hometown after the Spring Festival holiday in light of the severe restrictions on travel to contain the virus.

"We need to start training," Shane said. "We cannot stay in our homes for a long time. Of course safety is the most important priority, there is a large red carpet at the entrance to the building, and I ask for it to be cleaned every two or three hours.

Like all other sectors of the Chinese economy, the band has been hit hard by the virus.

At least 30 performances, some of which were due in Australia and Hong Kong, were postponed.