Agents said they noticed a bulge in the suspect's waist at airport security
The U.S. has confirmed that at least one American citizen is among the dead, and that another is among the injured receiving medical treatment.
Those on board the United States-registered vessel opened fire on Cuban troops who approached for identification, according to the Cuban Ministry of the Interior.
President Trump announced a plan to impose additional tariffs on countries that provide oil to Cuba, declaring a national security emergency.
Cuba has been cut off from Venezuelan oil shipments as U.S. forces seize tankers.
A U.S. military operation in Venezuela killed 32 Cuban officers over the weekend, the Cuban government said Sunday in the first official death count provided.