KUNMING -- The virus behind the latest cluster of COVID-19 cases in the city of Ruili, in Southwest China's Yunnan province, shared the same origin, gene sequencing results have shown.

Gong Yunzun, Party chief of Ruili, said at a press briefing on Saturday that the viruses from 14 COVID-19 cases reported in the city are very similar in their gene sequencing results, suggesting that they came from the same transmission source.

Gong said the viruses belong to the same group as those reported by Myanmar, adding that the virus gene sequencing results of 10 of the cases are exactly the same. No virus mutation has been found.

Dozens of new confirmed and asymptomatic COVID-19 cases have been reported in Ruili over the week during a citywide nucleic acid testing campaign.

In addition to administering coronavirus vaccines to local residents, the city bordering Myanmar started on Saturday to provide COVID-19 vaccinations free of charge to foreigners over the age of 18 who are living and working in Ruili.