A detainee, center, is escorted by U.S. military personnel at the detention facility on Guantanamo Bay U.S. Naval Base in Cuba (File)

U.S. Attorney General Michael Mukasey says military trials for suspected terrorists detained at the Guantanamo Bay prison will proceed, despite a key ruling Thursday by the U.S. Supreme Court.

In their narrow (5-to-4) decision, the justices ruled foreign terrorism suspects held at the U.S. naval base in Cuba can challenge their detentions in civilian courts.

Mukasey told reporters in Tokyo Friday he was disappointed with the decision, because it will lead to hundreds of challenges from so-called "enemy combatants."

Mr. Bush said in Rome Thursday he will abide by the court's ruling but said, in his words, "that doesn't mean I have to agree with it." He said his administration will study the opinion and determine whether additional legislation might be appropriate.

The Guantanamo Bay prison opened in 2002 and holds some 270 men with alleged terror links. Some of the detainees have been held for more than six years.

The Bush administration views the military commissions process, created specially for suspects in the war on terror, as a valid alternative to the U.S. federal court system, in part because of the need for some of the evidence to remain secret.

Thursday's decision is the third time the U.S. Supreme Court has repudiated the administration over granting detainees access to civilian courts. After the second ruling, the White House and Congress passed a law in 2006 to specifically deny Guantanamo detainees the right to habeas corpus (challenge their detentions in court).

The new ruling strikes down that provision.

Civil rights advocates have criticized the Guantanamo tribunals, saying they lack impartiality and are subject to political influence.

Some information for this report was provided by AFP and AP.