Firefighters use a hose to put out a fire at Hyundai Premium Outlet in the central city of Daejeon, Sept. 26. Yonhap

The death toll from an outlet mall fire in the central city of Daejeon has risen to four, officials said Monday, amid fears more deaths could come, as a search is under way for two missing people.

The blaze is believed to have started from the basement parking lot at Hyundai Premium Outlet in Daejeon, about 160 kilometers south of Seoul, at 7:45 a.m. and spread quickly on cardboard boxes, sending dark smoke filling the entire floor, according to witnesses and survivors.

This photo shows a fire that broke out at an outlet mall in the central city of Daejeon, Sept. 26. Yonhap

Two men, one in his 50s and the other in his 30s, were found with serious injuries and sent to a hospital, but later pronounced dead in the morning. Two more people died later, while a search is under way for two others, according to the officials.