Former Cuban President Raúl Castro has been charged in a U.S. indictment with murder and other crimes for his alleged role in the downing of two civilian aircraft operated by Miami-based exiles in 1996 off the coast of the Caribbean island.The allegations come as part of escalating pressure by the Trump administration on Cuba’s socialist government to open its economy to American investment and remove U.S. adversaries. In addition, a U.S. blockade of fuel and other goods has caused widespread blackouts, food shortages and an economic collapse on the island.Castro, now 94, was Cuba’s defense minister at the time the two small planes were shot down. They were operated by the exile group Brothers to the Rescue, which had been dropping leaflets over Havana urging Cubans to rise up against their government. Russian-made fighter jets downed the two unarmed civilian aircraft, killing all four men aboard the planes.Here’s what to know about Castro, the indictment and the 1996 incident.

What does the indictment allege?Castro is accused in the indictment of authorizing the use of deadly force against Brothers to the Rescue, after the group had flown planes that dropped pro-Democracy leaflets over Cuba in January 1996. U.S. prosecutors said Castro and his older brother, Fidel Castro, who was president at the time, were the final decision makers on orders to kill.In February 1996, Raúl Castro ordered Cuban military officials to begin training, using MiG fighter jets from Russia, on finding, tracking and intercepting the group’s small planes off the island’s coast, the indictment says. The two planes were shot down on Feb. 24, killing four U.S. nationals, including three U.S. citizens. A third plane managed to escape.