HUANGSHAN, China - More than 20 swimmers were hit by diarrhea and low grade fever on Saturday as the Chinese national swimming championships was underway at Central China's Huangshan city of Anhui province.

The sick athletes included Olympic champion Liu Zige and rising star Ning Zetao, who had withdrawn from the men's 50m freestyle competition on Saturday.

The local government was taking measures to investigate the emergency and the result will come out in 48 hours.

A total of 372 swimmers from all over China are competing in 38 events of the championships, which lasts from October 14-18.