Ottawa, May 13 -- Canadian health authorities said on Tuesday that nine people in Canada are being monitored as high-risk contacts linked to an outbreak of Andes hantavirus aboard the expedition cruise ship MV Hondius, though officials said the overall risk to the public remains low.

All four travellers remain asymptomatic and are being monitored by local health authorities, the agency said in a statement.

Officials said the isolation period could last between 21 and 42 days, beginning May 10, which was identified as the last day a confirmed case was aboard the vessel.

The Canadian government said passengers and crew who had been aboard the MV Hondius since April 1 would be temporarily barred from boarding flights to Canada, in coordin...