Cooking water is emerging as the likely source of a foodborne norovirus outbreak, predominately among security staff, at the Winter Olympics in South Korea.

As of Monday, Korea’s public health authorities had confirmed 194 cases of norovirus in the outbreak, according to the Korea Herald. No athletes have been confirmed with the highly contagious virus. Of the confirmed cases, 147 patients have recovered and returned to work, with 47 still in quarantine.

Cooking water at a facility in the PyeongChang, the host city for the games, was possibly contaminated, the Korea Centers for Disease Control and Prevention said in an interim report. The lodging facility housed more than 1,000 people, mostly private security staff for the Winter Games.

Korean authorities reported Monday that the number of new cases has fallen off since the lodging facility stopped serving meals. However, the Tribune News Service reported cases have been confirmed outside the mountain town of Pyeongchang.

Of the new cases added to the outbreak count on Monday, nine are in Gangneung, which is located on the coast. The venues for Olympic hockey and figure skating competitions are in Gangneung.

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