Northeast China's Liaoning province reported six new locally transmitted confirmed COVID-19 cases and three new locally transmitted asymptomatic carriers on Sunday, the province's health commission said on Monday.

As of Sunday, the province has 40 confirmed cases and 31 asymptomatic patients being treated in hospital.

The province's latest round of infections began on Dec 15, when four port workers handling cold-chain food products were found to be asymptomatic carriers in the port city of Dalian.

In response, Liaoning province has strengthened management on imported frozen foods.

It designated 27 cold storage areas as the first stop to receive frozen products on Dec 19 for nucleic acid testing and disinfection, as well as improved the closed-loop safety supervising and tracing systems.

Data from the provincial market regulation administration shows by Dec 24, the capacity of the province's first-stop cold storage is 668,700 tons.

In Dalian, there are eight cold storage facilities approved by the city's epidemic prevention and control headquarters and the provincial market administration, said Qu Shouwei, director of Dalian's administration for market regulation, during a news conference on Sunday.

All cold chain food imported from other countries or transferred via other domestic cities must first enter the designated cold storage facilities for centralized disinfection, testing and supervision.

Other cold storage areas should not keep imported cold-chain foods directly without being treated at designated cold storage spots, Qu said.

The city released a notification on Monday requiring all cold-chain food products containers and bulk cargo--both imported and from other domestic cities -- to be disinfected before leaving port in Dalian.

Related information on disinfection should be input into the import cold-chain food tractability platform for integrated management.