Cuban troops engaged a speedboat carrying 10 people after it approached the island and opened fire on the soldiers. The troops returned fire, killing four and injuring six, according to Cuban authorities.

Axar.az, citing AP, reports that the Cuban Ministry of the Interior stated that the passengers were U.S.-based Cuban nationals and accused them of attempting to infiltrate the country for terrorist purposes.

U.S. Secretary of State Marco Rubio clarified that the incident was not part of any U.S. government operation.

The confrontation, which is now under investigation in both Cuba and the United States, has the potential to further heighten tensions between the two nations.

Cuban President Miguel Díaz-Canel said Thursday that Cuba “does not attack or threaten.”

“We have stated this repeatedly, and we reiterate it today: Cuba will defend itself with determination and firmness against any terrorist or mercenary aggression that seeks to undermine its sovereignty and national stability,” he wrote on X.