July 30 (Reuters) - U.S. cruise liner Royal Caribbean Group said on Friday six guests on its Adventure of the Seas cruise ship had tested positive for COVID-19 during routine testing.

Royal Caribbean said four of the guests, who were not traveling together, were vaccinated and the other two were unvaccinated minors. Of the passengers who tested positive, only one had mild symptoms.

The guests were immediately quarantined and their travel parties and all close contacts were traced and tested negative, the company said. The guests and their travel parties will disembark later today and travel home.

The Adventure of the Seas cruise, which set sail from Nassau in the Bahamas on July 24, required all travelers aged 16 or older to be fully vaccinated and test negative before boarding. Those ineligible for the vaccine had to show a negative test result to travel.

Cruise operators, one of the sectors hit hardest by the pandemic, have been slowly restarting operations after more than a year of being docked at ports.

(Reporting by Aishwarya Venugopal in Bengaluru; Editing by Devika Syamnath)