The US case, unveiled on Wednesday, accuses Castro and five others in the shooting down of two planes belonging to Cuban-American group Brothers to the Rescue in 1966 - killing four people, including three Americans. Cuban President Miguel Díaz-Canel has called this and other charges levelled at Castro "a political manoeuvre, devoid of any legal foundation". US Secretary of State Marco Rubio has since said Cuba poses a "national security threat" and the likelihood of a peaceful agreement between the two countries is "not high". As the charges against Raúl Castro were announced, many Cubans were unaware and incommunicado due to the 20-hour blackouts continuing to grip the island. The US has imposed a near-total fuel blockade that has affected almost every facet of daily life. US President Donald Trump has repeatedly sought to exert pressure on Cuba and has openly discussed toppling its communist regime. The US has demanded political and economic reforms but the specifics are unclear beyond a leadership change. They could include a pledge to open up the economy to more foreign investment and a commitment to end the presence of Russian or Chinese intelligence agencies on the island. (BBC)