Two people on board a cruise ship in the Caribbean have tested positive for coronavirus, operator Royal Caribbean has confirmed.
The guests, who were sharing a room on the Celebrity Millennium, don't have symptoms and are in isolation.
Royal Caribbean restarted cruises in June after they were suspended for more than a year due to the pandemic.
Cruises were seen as hotbeds for the virus during the first half of last year, with a number of outbreaks.
Cruising is a global industry that, before the pandemic, was worth $150bn (£106bn) and supported about 1.2 million jobs.
The Celebrity Millennium is a week-long trip from St Maarten with additional stops in Aruba, Barbados and Curacao,
All guests had to show proof of vaccination and a negative Covid test before boarding, the company said. All on-board staff are fully vaccinated.
The two cases were confirmed during end of cruise testing and Royal Caribbean are conducting contact tracing, the company said in a statement.
Royal Caribbean has worked with the US Centre for Disease Control (CDC) to restart its sailings. The CDC gave cruises the go-ahead if 98% of crew and 95% of passengers are vaccinated.
During the start of the pandemic last year, a number of cruises suffered large outbreaks of Covid on-board.
The Diamond Princess hit the headlines in February 2020 after more than 600 people tested positive for the virus. At least nine people died, according to the CDC.