Coronavirus has been found on the packaging of imported squid, health authorities in China have announced.
Traces were discovered in the country's northeastern Jilin province.
One of the packages had arrived in the city via the provincial capital Changchun.
The area's Covid prevention office said the squid had been imported from Russia by a company in Hunchun city and brought to the provincial capital.
Anyone who may have bought the squid have been urged to get themselves tested.
One of the packages had arrived in the city via the provincial capital Changchun, Fuyu city's health office said on its official WeChat account on Sunday.
It asked people who had bought and eaten imported squid at the local Sanjia Deda frozen seafood wholesale shop Aug 24-31 to report to neighbourhood authorities and seek a Covid-19 test.
Chinese customs said on Friday they would suspend imports from companies for a week if frozen food products tested positive.
They added that a ban would last for a month if a supplier's products tested positive for a third time or more.
Mainland China has recently reported very few infections with the virus which emerged in Wuhan late last year, with just ten new Covid-19 cases on Saturday.
It says most recent cases come from people entering China from elsewhere.
In August, local authorities in two Chinese cities said they had found traces of the virus on cargoes of imported frozen food.
The World Health Organization said then it saw no evidence of Covid-19 being spread by food or packaging.
