Washington ? The Pentagon is preparing to release a dozen or more prisoners from the high-security compound for terrorist suspects in Cuba, possibly including some teenagers.

Some 660 prisoners from 42 countries are held at the Naval base at Guantanamo Bay, many captured during the war against al-Qaida in Afghanistan. Officials have declined to identify them or their countries or even say exactly how many are held.

An official said Monday that he believed juveniles were among those to be released. News that several boys between the ages of 13 and 16 were among the prisoners drew criticism earlier from human rights groups and a call for their immediate release.

One official said 20 to 30 prisoners would be released from the prison that was opened in January 2002. Another said the number was 12 to 15.

A military official initially told The Associated Press on Monday that 22 prisoners were transferred Monday from the Cuban facility. Later, a more senior Pentagon official said the report was mistaken, and no transfers had taken place.

Defense Department officials denied that the release was the result of a complaint by Secretary of State Colin Powell, who has pressed the Pentagon to move faster in determining the fate of the prisoners at Guantanamo, some of whom have been held a year and a half without charges or access to lawyers. The officials spoke on condition of anonymity.

In what officials have said was a strongly worded letter, Powell told Defense Secretary Donald H. Rumsfeld that eight allies had complained about the holding of their citizens.

Powell said that the way the situation was being handled was undermining efforts to win international cooperation in the war on terror.

The release has been in the planning process for several weeks, Pentagon officials said.

One official said the juveniles had been among those planned for release several weeks ago, but that it was logistically difficult to fly them out of Cuba at that time because U.S. troops were too busy with the war to topple and disarm Saddam Hussein in Iraq.