Authorities locked down a Chinese city bordering Myanmar on Wednesday, shutting most businesses and requiring residents to stay at home as a fresh outbreak of COVID-19 expanded.

Another 15 cases were found in Ruili in the last 24 hours, on top of six in the previous two days, สล็อต  health authorities in southwestern Yunnan province said.

The lockdown shut down all businesses and public institutions except hospitals, pharmacies and essential shops like grocery stores, according to a notice posted online. It affects the urban part of Ruili, which like most Chinese cities includes surrounding rural areas in its jurisdiction.

Authorities had earlier banned unnecessary travel in and out of the city on Monday, after the first cases were reported.

The latest cases were discovered during mass testing. They included both Chinese and Myanmar nationals in the city, which has an active cross-border trade. Authorities said they would step up border controls.

Myanmar had reported 3,602 new cases in last 24 hours, state media said Wednesday.

Elsewhere in China, 52 people who had arrived on a flight from Afghanistan five days ago tested positive for the virus, the Hubei provincial health commission said. Thirty have been classified as confirmed cases, while the other 22 did not show any COVID-19 symptoms. China does not include asymptomatic cases in its official tally.