CARACAS, Venezuela — A Venezuelan court has sentenced two former U.S. special forces soldiers to 20 years in prison for their part in a blunder-filled beach attack aimed at overthrowing President Nicolás Maduro.

Lawyers for the former Green Berets, Luke Denman and Airan Berry, said they were barred from the secretive jailhouse proceedings late Friday in what they consider a violation of their constitutional rights to a defense.

Maduro’s chief prosecutor announced the surprise decision late Friday.

“THEY ADMITTED THEIR RESPONSIBILITY FOR THE FACTS,” Tarek William Saab announced on Twitter, adding that proceedings will continue against dozens of other defendants accused of assisting in the May 3 raid. He did not offer details.

“Operation Gideon” was launched from makeshift training camps in neighboring Colombia and left at least eight rebel soldiers dead while more than 60 more were jailed.

Ex-Green Beret Jordan Goudreau, who operated a Florida-based security firm called Silvercorp USA, claimed responsibility for the failed attack and had hired his two former Army buddies to prepare a small cadre of deserting Venezuelan soldiers living at the makeshift camps. Venezuelan prosecutors have ordered his arrest. Goudreau is believed to be in the U.S., where he also is under investigation for possibly violating arms trafficking laws in connection to the botched incursion.

Denman and Berry, both decorated former U.S. service members, were found guilty of conspiracy, trafficking in illegal arms and terrorism, Saab said.

Lawyers for the men said the hearing was marred by irregularities.

Alonso Medina Roa said he was hired a month ago by the families of the two Americans but has so far been barred from meeting or speaking with his clients.

In violation of their constitutional rights to a defense, he said, Judge Máximo Marquez never informed him of Friday night’s proceedings at the headquarters of the SEBIN police, where the men are being held. They were represented instead by a public defender.

The two Americans arrested in a coastal fishing community have been paraded by officials on Venezuelan state TV as proof of their long-held claims that the United States is set on violently overthrowing Maduro’s socialist government.

The incident also prompted claims that U.S.-backed opposition leader Juan Guaidó had authorized Goudreau through a signed agreement to carry out the attack, executed by two of Guaidó‘s former political advisers in the U.S.

U.S. officials have denied any role in the attack but have not said what knowledge they had about the clandestine camps in Colombia, details of which were made public by an AP investigation two days prior to the raid. Secretary of State Mike Pompeo said Washington would use all possible means to win the freedom of Denman and Berry.

Mark Denman, brother of Luke Denman, said in a statement the families were “very disappointed” the men were not represented by their private legal counsel.

“With the trial behind us, we are now focused on assuring that during their detainment their rights are adhered to. This includes humane treatment, access to adequate medical care, communication with their families and attorneys,” he said.