Mexico's navy announced Thursday it has activated a search-and-rescue operation in the Caribbean to locate two sailboats carrying humanitarian aid to Cuba that have gone missing.

The two boats departed from Isla Mujeres, located in the Mexican Caribbean state of Quintana Roo, last week with Havana as their destination. The vessels were carrying nine crew members of various nationalities, according to a navy statement.

The boats failed to arrive in Havana as scheduled, prompting Mexican authorities to launch the search operation. The navy did not provide details about when the boats were expected to arrive or how long they have been overdue.

Isla Mujeres is a popular tourist destination off the coast of Mexico's Yucatan Peninsula, located approximately 500 miles from Havana across the Caribbean Sea. The navy statement did not specify the type or contents of the humanitarian aid being transported.

No further details were immediately available about the missing vessels, their crew members, or the scope of the ongoing search operation.