The Pentagon handed over on Monday the first list of everyone who has been held at Guantanamo Bay, Cuba — more than four years after the U.S. began using it as a detention center in its war on terror.

None of the most notorious terrorist suspects was included in the list delivered by the Pentagon to The Associated Press, raising questions about where America's most dangerous prisoners are being held.

The names of some 200 former prisoners have never been disclosed. Officials say 759 detainees have been held at the center since it opened. Of the total listed, more than a quarter — 218 — were Afghans. A total of 131 Saudis also passed through the prison gates at Guantanamo Bay Naval Base, perched on an arid slope above the Caribbean.

More than half the detainees were 25-34 years old, while three were 18 or younger and at least nine were over 61.

The handover marks the first time that everyone who has been held by the Defense Department at Guantanamo has been identified, according to Navy Lt. Cmdr. Chito Peppler, a Pentagon spokesman.

The names of all detainees held there were previously kept classified because of "the security operation as well as the intelligence operation that takes place down there," said Pentagon spokesman Bryan Whitman.

In a briefing in Washington, he did not explain why — if there was such a security risk — the Pentagon did not contest the AP's request for the release of the names, as it did with previous Freedom of Information Act requests for prisoner information. Just last month, the Pentagon released 558 names of current and former detainees to AP.

"This list takes us one step closer to our goal of fully reporting who has been swept into U.S military custody in Guantanamo, and how they and their cases are being handled," said David Tomlin, the AP's assistant general counsel. He added that the Pentagon did not give all the information the AP sought in a Freedom of Information Act request.

The new list, when compared to the one from April, shows the Pentagon released many Afghans who were swept up early in the war. More than 90 were transferred out of Guantanamo between January 2002 and the summer of 2004.

Anthony Romero, executive director of the American Civil Liberties Union, believes U.S. officials are trying to deflect international criticism of Guantanamo Bay by gradually moving out detainees.

"They are trying to slowly let the air out of the tires as a way to make the problem go away," Romero said.

The release of the names will help lawyers and other advocates track who has been held at the base and find former detainees to help investigate allegations of abuse, said Priti Patel, an attorney for New York-based Human Rights First.

While the release of Guantanamo names is welcome, human rights groups also want to learn the identities of all those held in Iraq, Afghanistan and secret locations, Patel said.

"There's still much more in darkness," she said.

For example, the United States has not disclosed where it is holding Khalid Shaikh Mohammed or Ramzi Binalshibh, who allegedly plotted the Sept. 11 terrorist attacks, and other captured top al Qaeda figures. The list released Monday also does not specify what has happened to former Guantanamo Bay detainees.

The fate of some is documented. All British nationals held at Guantanamo Bay, for example, were transferred back to Britain. But what has become of dozens of other detainees was not known.

Some could be free. Others could be in secret U.S. detention centers, or in torture cells of prisons in other countries.

Jumana Musa, an official with Amnesty International's Washington office, said there were rumors the CIA had a secret prison at Guantanamo Bay, an isolated base which Cuba granted to Washington by treaty a century ago.

Peppler, in an e-mail to the AP, said no such facility exists. Peppler did not address whether there was one in the past.

"Absolutely not," Peppler said. "There are no other detention facilities other than those under DoD control in Guantanamo Bay."

The AP sought the names, photos and other details of current and former Guantanamo Bay detainees through a Freedom of Information Act request on Jan. 18. After the Pentagon didn't respond, the AP filed a lawsuit in March seeking compliance.

The Pentagon later agreed to turn over much of the information. Motions are pending in court for additional information, including the height and weight of the roughly 480 detainees still at Guantanamo Bay to assist with news coverage of a hunger strike.

The Pentagon refused to release that information, arguing that medical records are private. The military said the hunger strike began in August and has involved a maximum of 131 detainees.

The Pentagon also argued that releasing photos of current detainees would damage U.S. intelligence gathering. Releasing pictures would make it easier for al Qaeda to retaliate against detainees suspected of cooperating with interrogators, said Paul B. Rester, the director of the Joint Intelligence Group at Guantanamo. That would make it harder for the U.S. to collect intelligence, Rester said in a May 10 affidavit filed in response to the AP's Freedom of Information Act suit.

"No human intelligence sources interested in cooperating with the United States officials under any hope of anonymity will be willing to do so if their photographs and names are publicly released," he said.

The U.S. military says 759 detainees have been held at Guantanamo Bay since the detention center began taking prisoners in the U.S. war on terror in January 2002. About 275 have been released or transferred.

The U.S. has filed charges against 10 detainees.

The Pentagon says another 136 detainees at Guantanamo have been approved for release or transfer, but their departure in some cases has been delayed as Washington tries to persuade their home countries to accept them and receive assurances they won't be treated inhumanely.