The current COVID-19 outbreak in the border city of Ruili in Southwest China's Yunnan Province was caused by a  coronavirus strain circulating in Myanmar, authorities said on Saturday.

Genomic sequencing of samples taken from the flare-up in the Chinese city shows that the virus was highly homologous with that in Myanmar, local health authorities said at a press conference. They added that the results confirm that the fresh cluster was not caused by a secondary transmission from other cases elsewhere in the country.

Authorities said they suspect the virus in Ruili was imported from Myanmar and that there is no link with strains detected in overseas arrivals in other parts of China.