After four lives were lost in an exchange of fire with Cuban security forces, Havana claimed that 10 people were on board the boat that opened fire on its soldiers. They were Cubans living in the US and the majority had "a known history of criminal and violent activity", and were trying to infiltrate the island and unleash terrorism, the government said.
The announcement came hours after Cuba said its soldiers killed four people and wounded six others aboard a Florida-registered speedboat that had entered Cuban waters and opened fire on the soldiers first, injuring an officer.
The Cuban government identified two of the boat passengers as Amijail Sanchez Gonzalez and Leordan Enrique Cruz Gomez, who are wanted by Cuban authorities. The government said it had also arrested Duniel Hernandez Santos, adding that he was "sent from the United States to guarantee the reception of the armed infiltration, and at this time has confessed to his actions."
The Caribbean nation said that one of the four killed was Michel Ortega Casanova. Three others have not yet been identified. Cuba said it obtained the details about the passengers aboard the boat from the suspects detained following the shootout, news agency Associated Press said in a report.
In past years, some of those US-flagged boats were laden with unidentified items headed towards the island, or they were going to pick up Cubans and smuggle them into the US. It is not unusual for skirmishes to erupt between Cuba's Coast Guard and US-flagged speedboats in Cuban waters, but there have been no recent reports of passengers opening fire or being killed, AP said.
US Secretary of State Marco Rubio had told reporters earlier that he was made aware of the incident and that the US is now gathering its own information to determine if the victims were American citizens or permanent residents.
US President Donald Trump's top diplomat refused to speculate on what happened, saying that it could be a "wide range of things," and that the US will not solely rely on what the Cuban authorities have provided thus far.
"Suffice it to say, it is highly unusual to see shootouts on the open sea like that. It is not something that happens every day. It is something, frankly, that hasn't happened with Cuba in a very long time," Rubio said.
He said both the US Department of Homeland Security and the US Coast Guard are investigating the incident and stressed that he wants to verify the facts.