Royal Caribbean International has been forced to cancel two cruises out of Singapore after Covid-19 cases were found among its crew.

The US-listed cruise giant said the sailings affected were those on Monday and Thursday aboard its 169,000-dwt Quantum of the Seas (built 2014).

Royal Caribbean told local media that a “small number of the crew had tested positive for Covid-19”, but it gave no exact numbers.

The company said the cruises were cancelled “in an abundance of caution” despite only 0.6% of the ship’s crew testing positive for the virus.

Royal Caribbean said the positive cases were immediately isolated, while close contacts were quarantined and tested.

“As per safety protocols, the ship will also go through a deep cleaning and disinfection,” the cruise line added.

Singapore’s “cruises to nowhere” have proved a popular option for the local population which until recently had faced severe travel restrictions.

The cruises were launched in November 2020 by two cruise lines — Genting Cruise Lines and Royal Caribbean International.

However, it has not all been plain sailing, with the first cruise on the Quantum of the Seas cut short over a suspected Covid-19 infection that later proved to be a false alarm.

On Monday, Singapore became the latest country to be added to the US Centers for Disease Control and Prevention’s (CDC) list of countries it advises citizens to avoid.

The South East Asian city-state was added to the list due to what the CDC described as “high rates of coronavirus infection”.

Since mid-December, the US government has added more than 60 countries and territories to its list of places to avoid, citing the Omicron coronavirus variant.

Early 2022 has seen a series of coronavirus outbreaks on cruise ships in North and South America, Europe and Asia despite strict health measures, giving new headaches to the pandemic-hit sector.

Safety bubbles that include tests and vaccine requirements were set up to reassure travellers when cruise travel resumed last year following a long hiatus that was imposed as the world scrambled to contain the virus.

In early January, Royal Caribbean’s 169,000-gt Spectrum of the Seas (built 2019), a vessel carrying 3,700 people, was ordered back to port in Hong Kong after nine people were found to be close contacts in an Omicron variant outbreak.