Cuban forces killed four exiles and wounded six others who sailed into Cuban waters aboard a Florida-registered speedboat on Wednesday and opened fire on a Cuban patrol, the Cuban government said at a time of heightened tensions with the United States.

Cuba’s Interior Ministry said the group was comprised of anti-government Cubans, some of whom were previously wanted for plotting attacks. They came from the United States dressed in camouflage and armed with assault rifles, handguns, homemade explosives, ballistic vests and telescopic sights, Cuba said.

An additional Cuban suspect was detained inside Cuban territory in connection with the plot, the statement said.

“According to preliminary statements from the detainees, they intended to carry out an infiltration for terrorist purposes,” the Interior Ministry said in an official statement.

The wounded were evacuated and receiving medical attention, while the Cuban patrol commander was also wounded, the ministry said.