Seventeen new cases have taken the total to 194, although 147 of those affected have already been released from quarantine, they said.
About 1,200 security guards were quarantined and replaced by hundreds of soldiers when the highly contagious bug first came to light last week.
Officials say they are doing everything they can to stop more people getting the virus, which causes diarrhoea and vomiting and can be spread by contaminated food and water.
Any illness spreading to the competitors would be a major embarrassment to hosts South Korea.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)