GUANTANAMO BAY US NAVAL BASE, Aug 22: US military authorities on Sunday defended the special trials for war on terror detainees that start this week as they stepped up security at the Guantanamo Bay base in Cuba for the hearings.

Four accused Taliban and Al Qaeda members - including the Australian David Hicks - are to be formally charged from Tuesday before military commissions which have been strongly criticized by lawyers and human rights groups.

Despite mounting legal challenges to the process in civilian courts, the US authorities refused to accept the criticism. "I am hopeful that people will see this process as a full and fair opportunity for each accused to have their case heard," said Lieutenant Susan McGarvey, a spokeswoman for the Defence Department's Office of Military Commissions which is running the hearings.

"And I hope that over the course of time people will see this as a proper venue for trying war crimes in the course of an ongoing conflict." Civilian legal experts say the tribunals - whose five members are all US military officers - do not meet international law.

They have highlighted the lack of independent review the lack of access to Guantanamo detainees for lawyers, and the use of secret evidence. "The system is stacked, so there is an inequality between the defence and prosecution," said Saman Zia Zarifa, an observer at the hearings for Human Rights Watch.

But the military spokesman said "each accused will get a full and fair hearing that is consistent with practice and national security." "You will see normal US standards here and I am sure you will see the normal adverserial system played out" said McGarvey.

The first arraignment on Tuesday will be for Salim Ahmed Hamdan, a Yemeni driver and bodyguard for Osama bin Laden. He will be followed on Wednesday by Hicks who is accused of conspiracy to commit war crimes and attempted murder.

The other two to be charged are Ali Hamza Ahmed Sulayman al-Bahlul, a Yemeni, and Ibrahim Ahmed Mahmoud al-Qosi, a Sudanese. All four are among the 585 detainees Taliban and Al Qaeda detainees held at Camp Delta in Guantanamo Bay.

Reporters were shown the former administrative building where the commissions will meet on Sunday. No video or photographic images can be taken near the building which will become the equivalent of a "secret facility" from Sunday, said Colonel David McWilliams another Defence Department spokesman.

Colonel Peter Brown back will be the presiding officer at the hearings but the US military has ordered that other members of the panel and the prosecution cannot be named. McWilliams said the commission officials "have concerns about their family members" as Al Qaeda has threatened "retribution" in the past if trials were held. -AFP