Two South Koreans were killed, and nine athletes and eight others were wounded early Saturday as a loft inside a nightclub collapsed in South Korea's southwestern city of Gwangju, where the 18th FINA World Championships was ongoing.

The loft, about 2.5 meters above the lower floor, inside the nightclub caved in on top of people at about 2:29 a.m. local time, killing two South Koreans identified only by their surnames Choi and Oh, according to the Gwangju Fire and Safety Headquarters cited by Yonhap news agency.

Nine athletes, who came to the city for the swimming competition, and eight others were injured. The nine swimmers included four Americans, two New Zealanders, one Dutch, one Italian and one Brazilian, six of them being women.

They were all water polo players, except for the Brazilian. Among the injured, there was no athlete in a critical condition though some of them underwent minor surgery for laceration.