Passengers aboard a cruise ship that set sail from Southampton may have norovirus, US authorities say.
The Centres for Disease Control and Prevention said 27% of the passengers aboard the Balmoral, operated by Fred Olsen Cruises, had become ill since the cruise began on April 16.
The CDC said 252 of the 919 passengers on the Balmoral were sick, as well as eight members of the 502-member crew.
Symptoms of norovirus include nausea, vomiting and diarrhoea.
The CDC said the ship has increased its cleaning and disinfection procedures. Two health officers and an epidemiologist boarded the ship during its stop in Baltimore, Maryland, last week.
Ethan Strimling, mayor of Portland, Maine, told the Portland Press Herald that he learned about the outbreak just before boarding the ship, which had docked at the city's harbour, for a tour on Sunday morning.
"I could see there were people wiping things down constantly," he said. "We got on to the elevators and they wiped the elevators down."
The Balmoral left Portland Harbour at 4pm local time on Sunday and is heading for Saint John, New Brunswick, the Press Herald said.
The ship is due to return to Southampton on May 20.