A woman receives an injection of the COVID-19 vaccine at a healthcare center in Shenzhen, south China's Guangdong Province, Dec. 30, 2020. (File photo: Xinhua)

SHENZHEN, May 22 (Xinhua) -- The city of Shenzhen in south China's Guangdong Province on Friday registered an asymptomatic infection of novel coronavirus, local authorities said Saturday.

The asymptomatic case was identified as a 44-year-old man from Yantian District's port area, whose work involved boarding global freight ships, said the district's headquarters on COVID-19 prevention and control.

All of the 54 close contacts of the asymptomatic carrier have been quarantined and tested negative in nucleic acid tests.

The district is home to Yantian port, a pivotal foreign trade port in China.