China on Tuesday reported the highest daily tally of new confirmed Covid-19 cases since January, driven by a surge in imported infections in southwestern Yunnan province , which shares a border with Myanmar. Mainland China recorded 65 new confirmed cases for July 19, compared with 31 a day earlier, the National Health Commission said in a statement. That was the most since January 30, when 92 new cases were reported. Imported infections accounted for most of the new cases reported for July 19, with Yunnan reporting 41 new cases originating from abroad, all of whom were Chinese nationals who had recently returned from Myanmar. The current bout of cases in Yunnan started on July 4, and has been concentrated in Ruili and Longchuan, two small cities on China’s border with Myanmar, which has been hit by a sharp uptick in infections since June. Ruili, battling its fourth outbreak since the pandemic started, reported seven new locally transmitted cases for July 19, while Longchuan had one. Proposed WHO Covid-19 origins study ‘inconsistent’ with China’s position Ruili is a key overland transit point for Yunnan, which has a 4,000km border with Laos, Myanmar and Vietnam. The Yunnan outbreak marks the second cluster of infections in China involving the highly contagious Delta strain, following an outbreak in southern Guangdong province in May and June. Yunnan vice-governor Zong Guoying promised on Sunday to establish a “fortress of iron” to stop further transmissions as he visited Ruili. In the prefecture of Xishuangbanna, which also shares a long and porous border with Myanmar, police have set up checkpoints on all roads to inspect all incoming and outgoing traffic. Travel outside Xishuangbanna’s urban centre of Jinghong was discouraged and special permits were also required to enter neighbouring cities of Lincang and Puer, as well as Ruili. Chinese health agency says Covid-19 vaccines are voluntary despite local rules For mainland China, 19 asymptomatic coronavirus cases were detected on July 19, compared to 17 a day earlier. China does not count asymptomatic infections as confirmed cases. China’s total Covid-19 cases has now reached 92,342, with deaths unchanged at 4,636.