Four detainees at the U.S. prison at Guantanamo Bay, Cuba, will be taken before a military judge for the first time next month, the first step toward being tried by military tribunals for their alleged involvement with al Qaeda, the Pentagon announced yesterday.

The four separate hearings are scheduled for the week of Aug. 23 and will be held in the newly constructed courtroom at the military prison on the Navy base. They will in some ways resemble the brief initial court appearance of former Iraqi leader Saddam Hussein before an Iraqi judge on July 1, a Defense Department spokeswoman said.

At the hearings, the presiding officer, retired Army Col. Peter Brownback III, will hear pretrial motions and, under the rules of military law, will be questioned by defense and prosecution lawyers about whether he has any biases or associations that could prevent him from serving, said the military spokeswoman, Navy Lt. Susan M. McGarvey.

Defense attorneys for the four intend to file objections to Brownback's plan to hold the hearings alone, without the four other officers who, with him, would constitute a military tribunal, which the Pentagon calls "commissions."

One of the detainees is David Hicks, an Australian former kangaroo skinner who converted to Islam and traveled the world, joining Muslim guerrilla movements, officials said. U.S. officials originally believed they had persuaded Hicks to plead guilty to some charges, but he apparently withdrew from that agreement after speaking to his lawyers.

The other three are Salim Ahmed Hamdan, a Yemeni national who the military says was a driver for al Qaeda leader Osama bin Laden; a Yemeni, Ali Hamza Ahmed Sulayman al Bahlul; and Ibrahim Ahmed Mahmoud al Qosi of Sudan. Bahlul and Qosi were allegedly bodyguards for bin Laden.