A norovirus outbreak at the Winter Olympics jumped to 232 cases after 33 new patients were diagnosed in areas away from the previous hotspot, officials said on Thursday.

Most of the earlier cases were at a youth centre where staff are housed, but the new patients are in staff accommodation in Pyeongchang and Gangneung, the main Games hubs.

Norovirus is highly contagious and causes diarrhoea and vomiting.

“We’re making sure that water quality is being monitored… and also hygiene is being monitored,” said Sung Baik-you, spokesman for the organising committee.

No athletes have been reported as affected, an organising committee official said, adding that water contamination has been traced as the source of the outbreak at the Horeb youth centre.