HANGZHOU, Dec. 29 (Xinhua) -- East China's Zhejiang Province reported one asymptomatic COVID-19 case on Tuesday, authorities said.

The asymptomatic case, who is an employee at a security service company in the provincial capital Hangzhou, was believed to be linked to a confirmed imported case, according to the provincial government.

A total of 137 close contacts of the asymptomatic case received nucleic acid tests, and as of 9 a.m., all results were negative.

Chen Guangsheng, executive deputy director of the provincial leading group office for the epidemic prevention and control, said the province has decided to implement a "14+7+7" health management measure for inbound personnel.

In addition to a 14-day concentrated quarantine, inbound personnel should undergo a week-long health observation at home plus another week of health monitor, with one round of nucleic acid testing arranged after each period.