As some schools across the country temporarily suspend face-to-face classes because of scattered clusters of COVID-19 cases or H1N1 influenza, experts have called for calm and reassured people not to worry.

A primary school in Hangzhou, Zhejiang province, had reported 10 students had tested positive for COVID-19 in the same class by Sunday, and it had conducted a four-day suspension of classes, according to the education bureau of Xihu district.

A class of the Primary School Attached to Xicheng Foreign Language School in Beijing also turned to online teaching for four days as there had been an increasing number of students with fevers since last weekend.

Test results showed that students were infected with influenza. A source from the school told Beijing News that since classes on the same floor use the same toilet, there was a risk of further spread of infection, so students had been asked to stay at home for a few days.

"There is a mild increase in the number of fever cases among children," said Zhang Qi, director of the pediatric department of China-Japan Friendship Hospital in Beijing, adding that after the new semester began, fever patients rose from about 10 to 20 people a day to 50 to 80 a day.

About a quarter of the patients are infected with influenza, but there were no new COVID-19 infections, she said.

"Children are one of the most vulnerable groups for being infected with diseases. Parents should encourage their children to wear masks, avoid crowded places and develop healthy lifestyles," she said, suggesting children with fever be quarantined at home to protect others from being infected.

Wei Sheng, professor of epidemiology at Southern University of Science and Technology, told People's Daily-affiliated Health Times that there was no need for the public to panic.

"It's an ordinary response for schools to suspend classes due to infectious diseases such as measles, chickenpox, influenza and hand-foot-and-mouth disease, in order to prevent further spread," Wei said.

On Wednesday, the Beijing Education Commission issued a notice on recent fever cases, saying that based on daily health management and infectious disease prevention and control arrangements, schools should focus on related work in winter and spring, such as strengthening the implementation of morning and afternoon inspection, tracking absence due to illness, and improving home-school communication.

They should actively guide parents and students to develop good hygiene habits and healthy lifestyles, scientifically adjusting and arranging sports and other activities according to seasonal changes.