BEIJING — Mass testing in a Chinese city bordering Myanmar has found nine more COVID-19 cases, bringing the total to 59 in a week-old outbreak involving the delta variant.

Authorities have locked down Ruili, blocking people from entering or leaving the city in Yunnan province and restricting residents in the urban area to their homes in a bid to contain the spread.

The latest confirmed cases include four Chinese and five Myanmar nationals, including an 11-year-old girl.

On the Myanmar side of the border, more than 250 people have tested positive in the city of Muse in June and July, the Global New Light of Myanmar newspaper reported Sunday, citing an unnamed official.

Myanmar, in the midst of a severe outbreak, reported 3,461 new cases nationwide and 82 deaths in the latest 24-hour period.