The island’s Ministry of the Interior said  on Thursday in a statement that Roberto Alvarez Avila died on March 4 from his injuries.

It added that the remaining injured detainees “continue to receive specialised medical care according to their health status”.

On February 26, authorities in Cuba said soldiers confronted a speedboat carrying 10 people as the vessel approached the island and opened fire on the troops. They said the passengers were armed Cubans living in the United States who were trying to infiltrate the island and “unleash terrorism”. Cuba said its soldiers killed four people and wounded six others.

“The statements made by the detainees themselves, together with a series of investigative procedures, reinforce the evidence against them,” the Cuban Interior Ministry said in its statement. It added that “new elements are being obtained that establish the involvement of other individuals based in the US”.

This week, Cuba said it had filed terrorism charges against six suspects who were on the speedboat. The government also unveiled items it claimed to have found on the boat, including a dozen high-powered weapons, more than 12,800 rounds of ammunition and 11 pistols.

Cuban authorities have provided few details about the shooting, but they said the boat was roughly 1.6 kilometres (1 mile) northeast of Cayo Falcones, off the country’s north coast.

They also provided the boat’s registration number, but The Associated Press news agency was unable to readily verify the details because boat registrations are not public in the state of Florida.

The shooting threatened to increase tensions between US President Donald Trump and Cuban authorities.

The island’s economy was, until recently, largely kept afloat by Venezuelan oil, which is now in doubt after a US military operation abducted and deposed former Venezuelan President Nicolas Maduro. (Aljazeera)