Preliminary hearings for the trial of five alleged 9/11 plotters were canceled this week over Tropical Storm Isaac are now set for mid-October, the US military said Friday.

The hearings, at which confessed September 11 mastermind Khalid Sheikh Mohammed is due to appear, are now due to take place from October 15-19 at the US naval base in Guantanamo Bay, Cuba, according to the US military commissions website.

Another series of hearings is set for December 3-7.

The hearings had already been postponed once so that the defendants could observe the Muslim holy month of Ramadan, and then pushed back a day when a derailed freight train in Maryland caused an Internet outage at the base.

They were finally scrapped over the imminent arrival of Tropical Storm Isaac, which is now due to hit southeastern Cuba on Saturday.

Mohammed is on trial along with his Pakistani nephew Ali Abd al-Aziz Ali, also known as Ammar al-Baluchi; Mustapha al-Hawsawi of Saudi Arabia and Yemenis Ramzi Binalshibh and Walid bin Attash.

The five face the death penalty if convicted for their roles in the 2001 attacks by Al-Qaeda militants in which hijacked planes were used to strike New York, Washington and Shanksville, Pennsylvania, killing 2,976 people.

The defendants have been held at the US "war on terror" detention center at Guantanamo Bay since 2006. Their trial is not expected to begin for at least a year.