Holland America Line has told guests they must wear face masks indoors on all Alaska cruises.

It said the policy change was due to a rise in COVID cases in the US state.

It follows a decision by Princess Cruises to reintroduce mandatory masks on three Alaska-based ships, Royal Princess, Majestic and Grand Princess.

Princess also insisted guests on an Island Princess cruise last week resumed wearing masks indoors after a number of positive COVID cases were detected onboard.

Holland America Line said in an email to guest: “Out of an abundance of caution due to the rise in positive COVID-19 cases throughout Alaska, all guests will be required to wear face masks at all times while indoors onboard during your cruise, except when eating or drinking or when in their staterooms.”

It is also recommending guests wear masks outdoors, particularly when physical distancing is not possible.

A HAL spokesperson said: “HAL will continue to adapt and adjust their policy (even by each sailing) depending on the number of cases and if/when local regulations require – across all ships and destinations.”