The current pandemic situation in Shijiazhuang, a city in Hebei province, shows obvious characteristics of disease clusters, and is expected to come under control within weeks, said a leading expert in Shanghai.

The spread of the COVID-19 virus usually obeys the rule of three developing phases: sporadic infections, outbreak in clusters, and wide spread in the community. The situation in Shijiazhuang is currently at the second phase, said Zhang Wenhong, leader of the Shanghai team of experts in the clinical treatment of novel coronavirus pneumonia cases.

"I'm deeply confident that the epidemic spread in Shijiazhuang will be controlled within a month," said Zhang during an online conference on Sunday.

He pointed out that China's diagnosis and quarantine capabilities and the government's experience of dealing with the pandemic has improved compared with a year ago.

Zhang, who also is director of the Department of Infectious Diseases at Huashan Hospital Affiliated with Fudan University in Shanghai, advised people to avoid public gatherings ahead of and during the upcoming Spring Festival in February.

"Individuals should stay alert to the pandemic but there's no need to be excessively nervous," he said.