Three Somali men being prosecuted on U.S. piracy charges say they were held naked, blindfolded and handcuffed for days without an interpreter, while another says he was threatened with being tossed overboard, lawyers said in court papers Monday.

Lawyers representing the Somalis also claim charges against one of the defendants should be dismissed because he's a juvenile.

In the case of two defendants, lawyers said statements the men made shouldn't be allowed in court because they weren't advised of their rights to remain silent or access to legal counsel.

The motions filed electronically Monday were among several submitted in U.S. District Court in Norfolk, Va., where five Somalis are being prosecuted for the alleged April 1 attack on the USS Nicholas off the coast of Africa.

The Nicholas defendants and six Somali men accused in the April 10 attack on the USS Ashland are scheduled to be arraigned July 28 on a new indictment that adds more charges. All face mandatory life terms if convicted of the piracy charges. Each has pleaded not guilty.

The government declined to respond Monday to the motions filed in the cases, saying it will respond in court.

The new filings expand on the defendants' version of what occurred when their small skiff encountered the Nicholas in the pirate-infested waters off north Africa.

In the case of Gabul Abdullahi Ali, he and two other defendants were held for more than three days handcuffed and blindfolded before an interpreter was made available, according to Ali's lawyer, William J. Holmes.

Ali doesn't recall ever being advised of his right to remain silent or to request counsel, Holmes wrote.

A lawyer for Mohammed Modin Hasan said an interpreter told him the U.S. Navy would toss him overboard if he didn't admit he was a pirate. Hasan told investigators he was captured while fishing and forced to participate in the attack on the Nicholas, lawyer James R. Theuer wrote.

Theuer also wrote that the alleged crimes happened before Hasan's 18th birthday.

"Defendant Hasan does not know the day, month, or year of his birth, but be believes himself to be 18 years old currently," Theuer wrote, adding the government has the burden to prove his age.

The government alleges the five defendants left Somalia in a seagoing vessel with two smaller craft attached, seeking a merchant ship. It claims the men were armed with assault weapons and a rocket-propelled grenade.

The five were captured after exchanging fire with the crew of the frigate, west of the Seychelles.

Seeking to dismiss the piracy charges, lawyers for three of the defendants said there was "no conceivable way" the men in a small skiff could pirate a heavily armed navy frigate with a crew of 100 highly trained sailors.

Lawyers for the accused Ashland pirates have also made the same legal claim.