Four people were killed and six others ‌were wounded on Wednesday after a speedboat from Florida entered ​Cuban waters and opened fire on Cuban forces, who returned fire, Cuba’s interior ministry said at a time of heightened tensions with the United States.

The wounded were evacuated and receiving medical attention, while the Cuban patrol commander was also wounded, Cuba’s interior ministry said in a statement, adding that the matter was under investigation to ​clarify exactly what happened.

The highly unusual incident took place as the United States has blocked virtually all oil shipments to the island, increasing pressure ⁠on the Communist-run government. American forces captured Venezuelan president Nicolas Maduro in Caracas on January 3rd, removing a ‌key ‌Cuban ​ally from power.

Florida attorney general James Uthmeier said he was ordering prosecutors to open a separate investigation in conjunction with other state and federal law enforcement partners, saying the Cuban ⁠account could not be trusted.

US Representative Carlos ​Gimenez, a Republican whose district includes the southern tip of ​Florida, called for a federal investigation, saying the incident raised serious concerns about the use of lethal force against a ‌vessel registered in the United States.

The speedboat came within ​one nautical mile of a channel on Falcones Cay, on the north coast of Cuba about 200km east of Havana, when it was approached ⁠by five members of a ​Cuban border patrol unit, Cuba said. The speedboat then opened fire, wounding the commander of the Cuban vessel, the statement added.

None of the dead or wounded aboard the encroaching vessel were identified, but Cuba said it was registered in Florida with the number FL7726SH.

“Faced with the current challenges, Cuba reaffirms its commitment to protecting its territorial waters, based on the principle that national defense is a fundamental pillar for the Cuban state in safeguarding its sovereignty and stability in the region,” the Cuban statement said.

The US State Department ‌did not immediately respond to ⁠a Reuters request for comment.

The Florida attorney general announced the Office of Statewide Prosecution would begin its own probe, saying in a Facebook post, “The Cuban government cannot be trusted, and we will do everything in ‌our power to hold these communists accountable.”

Gimenez, the Florida congressman, said he had asked the US State Department and military to look into ​the matter, in which he accused Cuba of executing four people. He did ​not cite evidence.

“United States authorities must determine whether any of the victims were US citizens or legal residents and establish exactly what occurred,” Gimenez said. – Reuters