The United States has issued a federal criminal indictment against Raúl Castro, Cuba’s former president, on Wednesday, and five others in a significant escalation of the Trump administration’s campaign to oust the country’s six-decades-old communist regime.

The 94-year-old political figurehead was charged in Miami, Florida, with conspiracy to kill US nationals, four counts of murder and two counts of destruction of aircraft, according to court filings obtained by CBS.

Other defendants are a fighter pilot who was initially charged in connection with a 1996 incident in which four men were killed by the Cuban military when their aircraft were shot down during a humanitarian mission in the Florida Straits.

Castro is alleged to have given the order to open fire.

The indictment comes at a time of heightened tension between the US and Cuba, with Donald Trump threatening military action against the Cuban government, and an energy crisis created by a tight US oil embargo causing rolling blackouts and prompting protests in the capital.

Miami’s Freedom Tower, where more than half a million Cuban refugees were processed as immigrants between 1962 and 1974 after fleeing Fidel Castro’s 1959 revolution, provided a symbolic backdrop for the announcement.

Raúl Castro allegedly authorized the 24 February 1996 shooting down of two small planes belonging to the Miami-based Brothers to the Rescue volunteer group of exiles, which would scour the 90 miles of water between Cuba and the Florida Keys for refugees. Four men, Armando Alejandre Jr, Carlos Costa, Mario de la Peña and Pablo Morales, died after their Cessnas were hit by missiles fired from MiG fighter jets from the Cuban air force.

Raúl Castro stepped down as president in 2018, and resigned as secretary of Cuba’s communist party three years later, but remains one of the most powerful figures in Cuban politics. Fidel Castro died in 2016 at the age of 90.

It is uncertain if he will ever face a US court to answer the charges.

Also on Wednesday, Marco Rubio, the US secretary of state, posted a message to the Cuban people on X. In Spanish, he said: “The reason you are forced to survive without electricity is not due to an oil blockade by America.

“No electricity, fuel or food is because the people who control it have plundered billions of dollars, but nothing has been used to help the people.”

Carlos Cossio, Cuba’s deputy minister of foreign affairs, responded in his own post on X.

“The reason why the US secretary of state lies so repeatedly and unscrupulously when referring to Cuba and trying to justify the aggression imposed on the Cuban people is not ignorance or incompetence,” he wrote.

“He knows well that there is no excuse for such a cruel and ruthless aggression.”

Earlier, in Washington DC, a group of Cuban-American Congress members welcomed Castro’s indictment at a press conference.

“Today is a glorious day for those Cubans who had to leave their homeland unwillingly, the people that we represent in the city of Miami, only because of the cruelty of the wickedness of a group of gangsters, the Castro family, who did nothing but seize the island to turn it into their own business,” said Maria Elvira Salazar, who represents south Florida.

“After six decades of tragedy, misery, of distress, Cubans will be free soon, and there are no words to describe the joy they feel.”

The Republican Florida congressman Carlos Giménez told reporters that the Brothers to the Rescue volunteers were trying to save lives when they were attacked.

“They were just looking for these rafters in the middle of the Florida Strait so that they wouldn’t die, and then they report the position to the Coast Guard, that’s all they were doing,” he said.

“They weren’t carrying drugs, they weren’t doing anything illicit, and they were international waters, and they were American citizens.

“For far too long this incident has gone without any repercussions for any of the people, or at least the person most responsible for this act, which was Raúl Castro.

“Why it’s taken 30 years, I don’t know why, but the number one job of any government is to protect its citizens. Finally, this administration, the Trump administration, has taken notice of that and said, ‘Yes, we will protect American citizens.’ And yes, maybe justice comes a little late in this case, but justice will be served.”

Salazar said she hoped Cubans on the island would continue to react to the US pressure, and Castro’s indictment, by protesting against their government.

“The message is for the Castro family: understand this well, that your days are over,” she said.

“A federal indictment is serious stuff. [Venezuelan president Nicolás] Maduro thought Trump was fooling … and look where Maduro is today, in a federal prison in New York.

“So we are sending the message to the Castro family, it’s time for you to leave. It’s time for you to heed the signal from the White House, do not fall into the abyss.

“You have the option not to wind up where Maduro is. You can leave now and let the island in the hands of the opposition forces, in the hands of freedom, so that destiny can bring Cuba to a different place.”

Wednesday’s events follow a further increase in tensions between the US and Cuba over a report published by Axios alleging Havana had acquired more than 300 military drones, and had discussed plans to use them to attack the US naval base at Guantánamo Bay, US navy vessels and Key West, Florida.

The Axios report said the allegation could be used by the Trump administration as a pretext for a military assault similar to that which ousted Maduro in January.

Cuba’s president, Miguel Díaz-Canel, warned in a post on X that any US military action against his country would lead to a “bloodbath”.

“Cuba does not represent a threat,” Díaz-Canel said.