President Barack Obama will restart Bush-era military tribunals for a small number of Guantanamo detainees, reviving a fiercely disputed trial system he once denounced but with new legal protections for terror suspects, U.S. officials said Thursday.

Obama suspended the tribunals within hours of taking office in January, ordering a review but stopping short of abandoning President George W. Bush's strategy of prosecuting suspected terrorists.

Obama's decision to resume the tribunals is certain to face criticism from liberal groups, already stung by his decision Wednesday to block the court-ordered release of photos showing U.S. troops abusing prisoners in Iraq and Afghanistan — a reversal of his earlier stand on making the photos public.

Officials spoke about the military commission decision only on condition of anonymity, saying some of the details were not final. An announcement was expected Friday.

The tribunal system — set up after the military began sweeping detainees off the battlefields of Afghanistan in late 2001 — has faced repeated challenges from human rights and legal organizations because it denied defendants many of the rights they would be granted in a civilian courtroom.

An administration official familiar with Obama's decision said between 10 and 20 of the 241 detainees currently at the detention center in Guantanamo Bay, Cuba, would be tried by military commissions.

Thirteen other detainees — including five charged with helping orchestrate the Sept. 11 attacks — already have been moved into the system and are expected to be tried there.

The rest of the detainees would either be released, transferred to other nations or tried by civilian prosecutors in U.S. federal courts, an official said. It's also possible that some could continue to be held indefinitely as prisoners of war with full Geneva Conventions protections, according to another senior U.S. official.

Obama faces two deadlines: his 120-day review of the tribunals ends Wednesday, and on May 27 the trial of Ahmed al-Darbi, a Saudi accused of plotting to attack a ship in the Strait of Hormuz, is scheduled to begin.

The new decision will delay the trials for several more months, the officials said. Obama is adding some changes to the commissions before they are restarted, including expanding the detainees' legal protections by restricting hearsay evidence that can be used against them, according to two officials.

The delay would give the administration time to adjust the system and allow Congress to review any rule changes or pass legislation altering the military commission law.

The decision to restart the process puts the administration in a race against the clock to conclude commission trials before the Navy prison is closed, by January 2010.

If the trials are still going on, the detainees might have to be brought to the United States, where they would receive even greater legal rights.