Seoul, Aug 16 : New Covid-19 cases in South Korea increased to 279 on Sunday, a five-month high, mainly due to a surge in church-related infections in the greater Seoul area. This brought the country's total caseload to 15,318, according to the Korea Centers for Disease Control and Prevention (KCDC). Of the total, 267 were locally transmitted cases, reports Yonhap News Agency. It marks the highest figure since March 8 when the new daily infections stood at 367 after hitting a record high of 909 on February 29, with Daegu and its neighbouring North Gyeongsang province at the center of the mass outbreak. It also marked a three-digit number for the third straight day, following 103 infections on Friday and 166 on Saturday. As of Sunday, infections tied to the Sarang Jeil Church in northern Seoul have increased to 249, while cases linked to the Woori Jeil Church in Yongin, south of Seoul, increased to 126. Local authorities have ordered the churches' congregations to undergo Covid-19 tests. Alarmed by a resurgence of infections in recent days, the government raised social distancing in Seoul and its neighbouring areas by one notch to Level 2 in the three-tier system Sunday for two weeks. On Sunday, President Moon Jae-in warned of stern responses to unlawful acts by some church members, reports Yonhap News Agency. "It is a clear challenge to the national disease control and prevention system, and an unforgivable act that threatens the lives of the people," Moon wrote on his Facebook page, adding the government will take "very stern and strong" measures even by resorting to compulsory means. He said the coronavirus outbreak is at a serious stage, and the government will make all-out efforts to get the virus under control. South Korea, meanwhile, reported no additional fatalities, keeping the death toll at 305. /IANS