(CBS) Three terror suspects 16 years and younger are being interrogated at the U.S. detention camp in Guantanamo Bay, Cuba, the military said Wednesday, setting off renewed outrage among rights advocates.

The teenagers are held in a "communal setting" separate from adult detainees' individual cells, but all were "captured as active combatants against U.S. forces" and are considered enemy combatants, said Lt. Col. Barry Johnson, chief spokesman for the mission.

Johnson would say only that the teenagers are "very few." However an official at the camp who spoke on condition of anonymity Wednesday said there were three youths.

Johnson would not say how old the youngest prisoner is. He confirmed their presence Tuesday following a report by Australia's ABC television that youths were being held at the camp.

The news brought fresh criticism from human rights groups opposed to the indefinite detention of the roughly 660 males from 42 countries held at Guantanamo on suspicion of links to al Qaeda terrorist network or Afghanistan's ousted Taliban regime. They have not been charged or allowed access to lawyers.

"That the U.S. sees nothing wrong with holding children at Guantanamo and interrogating them is a shocking indicator of how cavalier the Bush administration has become about respecting human rights," said Amnesty International spokesman Alistair Hodgett.

Human Rights Watch said the United States was exacerbating a contentious situation.

The detention of youths "reflects our broader concerns that the U.S. never properly determined the legal status of those held in the conflict," said James Ross, legal adviser for Human Rights Watch in New York.

Holding "captured children ... obviously makes the problem worse."

Johnson said officials determined some detainees were younger than 16 during medical and other screenings after their arrival. He said all the youths were brought to Guantanamo after Jan. 1.

In September, Canadian officials reported that a 15-year-old Canadian had been captured on July 27 after being badly wounded in a firefight in eastern Afghanistan. Prime Minister Jean Chretien said he was seeking consular access to the youth.

Last week, Toronto's Globe and Mail newspaper reported that the youth, now 16, is being held in Guantanamo and that U.S. officials have refused access to Canadian officials.

The newspaper quoted unidentified sources as saying that the youth allegedly threw a grenade that killed Sergeant 1st Class Christopher James Speer, 28, Albuquerque, New Mexico.

The Globe and Mail said U.S. officials would want to interrogate the Canadian because his father has been identified as a senior financial leader of al Qaeda.

All those detained at Guantanamo are being interrogated for suspected links to al Qaeda or the ousted Afghan Taliban regime that harbored the network.

Johnson said juveniles are being held because "they have potential to provide important information in the ongoing war on terrorism."

He said "their release is contingent on the determination that they are not a threat to the (U.S.) nation and have no further intelligence value."

Lawyers have blamed the indefinite detentions for increasing depression and suicide attempts at the camp, which received the first detainees in January 2001.

Johnson reported a repeat attempt at suicide Monday night by a detainee who was under close supervision in the acute care unit of a new mental health ward.

That brings the number of suicide attempts to 25 by 17 individuals, with 15 attempts made this year, according to the military.

Doctors have noticed improvement in the condition of a detainee who suffered brain damage in a suicide attempt three months ago at Guantanamo Bay, Cuba, a U.S. official said Monday.

The detainee has been unable to talk or walk since he tried to hang himself Jan. 16, military officials say.

The man, whose identity and nationality has not been released, is being fed through a tube, Johnson said.