BEIJING (REUTERS) - China's capital Beijing ramped up efforts to curb Covid-19 infections, ordering checks among cold-chain firms and urging residents to cut unnecessary gatherings, as the city reported an uptick in local cases weeks before the Winter Olympics.

Beijing had three domestically transmitted infections with confirmed symptoms on Wednesday , including one previously reported as a local asymptomatic carrier for Tuesday, according to local health authority data on Thursday (Jan 20).

That compared with one local confirmed infection for Tuesday.

The city has reported less than ten local Covid infections since Jan 15, with both the Delta and Omicron variants detected, a tiny case count compared with the rest of the world.

However, the city and China are still working under guidelines of getting any virus flare-up under control as soon as possible.

The strategy takes on extra urgency as Beijing and neighbouring Hebei province will host the Winter Olympics from Feb 4, while the ongoing Chinese New Year travel season raises the risk of virus transmission nationwide.

The city of Beijing should immediately launch full inspections over its cold-chain industry and make the testing of staffers and goods more frequent, the city government said in a statement late on Wednesday, after some infections were found to be cold storage workers.

Residents are advised to reduce movement and unnecessary gatherings, while children, the elderly and people in weaker health should avoid crowded public places, the city's health authority said in a statement on Wednesday.

China is also ramping up its coronavirus testing regime after linking at least two Omicron cases in the country to international parcels. 

Residents in the southern city of Guangzhou who received overseas mail between Jan 16 and 19 were told on Wednesday to take a test within three days. Local authorities are also rolling out a free programme from Thursday that will see anyone who has accepted an international package tested within three to seven days.

Guangzhou has not found an Omicron case in community transmission, but the increased scrutiny follows the detection of an infection in the nearby technology hub of Shenzhen that was linked to mail.

More than 1,300 miles north in Beijing, the local government has asked residents to minimise purchases from high-risk countries and disinfect parcels thoroughly when unpacking after its first positive result for the variant was found to have touched mail shipped from Canada through the US and Hong Kong.

Nationwide, China reported a total of 43 locally transmitted infections with confirmed symptoms for Wednesday, according to a statement by the National Health Commission on Thursday, down from 55 a day earlier.

There were no new deaths, leaving the death toll at 4,636.

As of Wednesday, mainland China had 105,411 confirmed cases, including both local ones and those arriving from overseas.