Cuba’s government said late Wednesday that the 10 passengers on a boat that opened fire on its soldiers were armed Cubans living in the U.S. who were trying to infiltrate the island and unleash terrorism.

Axar.az informs, citing AP, the announcement came hours after Cuba said its soldiers killed four people and wounded six others aboard a Florida-registered speed boat that had entered Cuban waters and opened fire on the soldiers first, injuring one Cuban officer.

Cuba’s government said the majority of the 10 people on the boat “have a known history of criminal and violent activity.”

U.S. Secretary of State Marco Rubio had told reporters earlier that he was made aware of the incident and that the U.S. is now gathering its own information to determine if the victims were American citizens or permanent residents.