September 11 attacks
September 11 attacksReuters

Five men accused of planning and aiding the September 11 terror attacks will go on trial in 2021.

The five, currently held in Guantanamo Bay prison, could face the death penalty if they are convicted at the military commission.

The suspects include Khalid Shaikh Mohammed, the "mastermind" behind the September 11, 2001 attacks and other terrorist plots. Mohammed, also known as KSM, is an Al-Qaeda leader.

The other four defendants have been identified by The Guardian as Walid bin Attash, who allegedly ran an Al-Qaeda training camp in Afghanistan where two of the hijackers were trained; Ramzi bin al-Shibh, a Yemeni accused of helping organize logistics for the attack; Ammar al-Baluchi, alleged to have played a critical role in funding the hijackers and organizing their flight school training; and Mustafa Ahmad al-Hawsawi, a Saudi accused of acquiring cash, credit cards and clothing for the hijackers.

The group of five, who have been held at Guantanamo Bay since September 2006, have been charged by the US with terrorism, hijacking, and nearly 3,000 counts of murder, due to their alleged roles in planning and providing logistical support for the plot.

Before being brought to Guantanamo Bay, they were held in CIA detention facilities.

Their charges were formally read to them in May 2012.

The deadline, January 11, 2021, was set by US Air Force Colonel and military judge W. Shane Cohen for the purpose of creating a deadline for the submission of evidence. He noted that the trial will "face a host of administrative and logistics challenges."

However, The Guardian noted that there is no guarantee that the trial will begin before the twentieth anniversary of the attacks.

According to The New York Times, Cohen will begin "a series of hearings next month with witnesses in an effort by the defense teams to exclude confessions the defendants made to FBI agents in early 2006 as tainted by the years of CIA torture."