A Venezuelan court sentenced two former US special forces soldiers to 20 years in prison for their part in a failed beach attack aimed at overthrowing President Nicolas Maduro, prosecutors said on Friday. Former Green Berets Luke Denman and Airan Berry admitted to taking part in the May 4 operation orchestrated by a third ex-US soldier who remains in the United States, Venezuelan's chief prosecutor Tarek William Saab wrote on Twitter. "They admitted their responsibility for the facts," Mr Saab wrote, adding that the case will continue for dozens more defendants. He did not elaborate. Operation Gideon was launched from makeshift training camps in neighbouring Colombia and left at least eight rebel soldiers dead, while a total of 66 were jailed. Former Green Beret Jordan Goudreau, who operated a private Florida-based security firm called Silvercorp USA, claimed responsibility for the failed attack. Venezuelan prosecutors announced that Denman and Berry, both decorated servicemen, were found guilty of conspiracy, trafficking in illegal arms and terrorism. The two Americans arrested in the coastal fishing community of Chuao have appeared on Venezuelan state TV as proof of officials' long-held claims that the UAS is set on overthrowing Mr Maduro's socialist government. The incident also led to claims that US-backed opposition leader Juan Guaido had authorised Mr Goudreau through a signed agreement to carry out the attack, executed by two of Mr Guaido's former political advisers. Mr Guaido and US officials denied any role in the attack. Secretary of State Mike Pompeo said Washington would use all possible means to win the freedom of Denman and Berry. A day before authorities announced that the two ex-Green Berets were sentenced, Venezuelan authorities opened the trial of six American executives of the Houston-based Citgo company. The six were arrested two years ago in Venezuela on corruption charges. The case had lingered for months until former New Mexico governor Bill Richardson met personally in July with Mr Maduro in Caracas to urge they be released so they could return home. Both play out amid hostility between Washington and Caracas. The Trump administration last year threw its support behind opposition leader Mr Guaido, who declared he was Venezuela's legitimate president, vowing to oust Mr Maduro. Mr Guaido blames Mr Maduro for the once wealthy nation's economic and social collapse, while the socialist leader said Washington was manipulating Mr Guaido to steal the nation's vast oil wealth.