South Korea has reported 51 more confirmed coronavirus cases as new clusters emerge in the densely populated Seoul area where people have been increasingly venturing out despite government warnings against complacency. Thirty-five of the new cases are in the capital region, which is at the center of a COVID-19 resurgence threatening to erase earlier gains against the virus. Authorities are struggling to trace contacts and predict infection routes as new clusters pop up. Hundreds of infections have been linked to nightspots, church gatherings, restaurants and low-income workers who couldn’t afford to stay home. Officials are resisting calls to reimpose stronger social distancing guidelines, concerned about hurting the economy.