The control work of the novel coronavirus pneumonia should not be relaxed especially when people gradually return to work and schools gradually reopen, even though the country is seeing a slowing increase in the number of new confirmed patients, a health official said on Friday.

"It's not the time to be blindly optimistic, as the epidemic is still severe and has the risk of rebound, although the World Health Organization gave a positive comment on our prevention and control work," Yu Xuejun, deputy head of the National Health Commission, said at a news conference in Wuhan.

As more provinces have already adjusted emergency response level in line with their own situations, Yu called for the provincial governments to make better preparation to ensure the disease prevention as enterprises and schools gradually reopen.

"Lowering the emergency response level means to cancel some restrictions, and the reopening represents more population flows," he said, adding that it will bring pressure for the epidemic prevention and control.

"It will bring many uncertainties for the epidemic control, which means our prevention and control works would face difficulty."

To lower the risk, the commission has demanded all the local authorities to draft a prevention plan and make full preparation to ensure it can give a scientific, accurate and timely resolution when new confirmed cases are reported during the reopening, Yu said.

"The most important is that relevant authorities and medical institutes take urgent measures to find out, report, quarantine and treat patients as early as they can," he said. "They should also improve epidemiological studies and trace those who have contact with the patients to ensure no one is left behind."

As local authorities have been urged to intensify health monitoring of employees and guided workers to strengthen self-prevention, Yu said the commission also suggested to add special trains, make more spaces between passengers, disinfect coaches and test body temperature to reduce the risk of the virus spreading in transportation.

"We clarified responsibilities of communities, employers and schools and strengthened control and monitoring in places such as shopping malls, hotels, and nursing homes," he said. "In addition, we issued 15 technical guidelines for residential areas, enterprises and schools to help the public know more about the self-prevention and health knowledge."

The commission will also dispatch teams to guide and inspect the prevention plan and medical force of each provinces municipalities and autonomous regions to make sure the epidemic does not rebound.