TAIPEI—Taiwan reported its first domestically transmitted case of the highly contagious Delta variant of the coronavirus on Saturday, tightening controls in a southern part of the island where the cases have occurred. Taiwan is battling a cluster of domestic infections, almost all of them due to the previously globally dominant Alpha variant, though numbers are steadying and the outbreak has been comparatively small. Six people in Pingtung county had been confirmed to have the Delta variant, including two who returned this month from Peru, where they are suspected of bringing the infection from, said Health Minister Chen Shih-chung. One of them has been classified as a domestic infection, rather than within the family who arrived from Peru. The government is carrying out mass testing in the area where the cases were reported, quarantining all suspected contacts. It has ordered supermarkets, restaurants, and wet markets closed for three days, Chen said. …