PYEONGCHANG, SOUTH KOREA (AFP) - 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 (Feb 15).

Most of the earlier cases were at a youth centre, but the new patients are coming from 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 Games 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.