Parts of a small city in southwest China that shares a border with Myanmar went into a full lockdown as local authorities wrestled with the city's fourth outbreak of the new coronavirus since the pandemic began.

Residents in the main areas of Ruili, a city in Yunnan province with a population of about 270,000, were told to quarantine themselves at home as schools and businesses shut. Some markets, hospitals and pharmacies remained open, Reuters reported.

Yunnan reported 15 new confirmed locally transmitted coronavirus cases for July 6, with all cases in Ruili. That compares with three cases per day in the city reported for July 4 and July 5.