Military prosecutors in the United States have filed new charges against self-described 9/11 mastermind Khalid Sheikh Mohammed and four alleged co-conspirators held at Guantanamo Bay.
Prosecutors have recommended that the trial be a capital case, which could bring the death penalty.
Other defendants facing new charges are Walid bin Attash, Ramzi Binalshibh, Ali Abdul Aziz Ali and Mustafa Ahmed al Hawsawi.
All five had previously been charged at the US detention centre in Cuba over the attacks.
The BBC reports Khalid Sheikh Mohammed has been charged before but the charges were dropped because US president Barack Obama wanted him to stand trial on American soil in a civilian court.
The Congress blocks that plan by prohibiting the transfer of any Guantanamo Bay detainees to the US, so after a senior military official signs off on the fresh charges, Khalid Sheikh Mohammed will stand trial in Guantanmo.
Khalid Sheikh Mohammed was captured in Pakistan in March 2003 and sent to Guantanamo in 2006.
American prosecutors say he has confessed to involvement in a host of terrorist activities in addition to the September 11 attacks on New York and Washington.