Dozens of private security guards at the Pyeonchang Winter Olympics in South Korea have been taken to hospital with norovirus, prompting organisers to call in soldiers as guards instead.
Vomiting and diarrhoea hit the security staff on Sunday.
Some 1,200 of the guards have been withdrawn from Olympics sites, with 41 having reported experiencing symptoms.
Hand sanitiser has now been distributed and the head of the organising committee has apologised.
The Pyeonchang Games are due to start on Friday.
Games spokesman Christophe Dubi said that operational measures had been put in place to avoid further outbreak of the highly contagious virus in respect of international standards.
"Very stringent measures are in place when it comes to food and beverages," he said. "As soon as a case is reported then all the area gets disinfected," he added.
The withdrawn security staff have been replaced by 900 soldiers.
The president of the organising committee of the Games, Lee Hee-beom, said all venues were being used for training, and athletes were settling in to their accommodation.
"I would like to apologise for this," he said.
"Our disease control centre [and] other related government agencies here are now discussing countermeasures," Mr Lee said, adding that the measures "will be announced soon".
At last year's World Athletics Championships in London, several athletes were forced to pull out of the competition when authorities discovered an outbreak of norovirus at a hotel.