WASHINGTON — The Pentagon on Friday officially dropped military charges against the accused mastermind of the 9/11 terrorist attacks and four other alleged conspirators, a development that likely foreshadows their transfer to New York City to face charges in a civilian federal court.

The Pentagon said the dismissal of the charges "without prejudice" against alleged plot leader Khalid Sheikh Mohammed and the others, Walid Bin Attash, Ramzi Bin al Shibh, Ali Abdul Aziz Ali and Mustafa Ahmed Adam al Hawsawi, was a procedural step to clear the way for their civilian trials.

There was no word on when indictments would be issued in New York against the men or when they would be transferred from Guantanamo to the United States.

Attorney General Eric Holder announced on Nov. 13 that the five men would be tried in federal court for the 9/11 attacks, which killed nearly 3,000 people. Criticism quickly followed by Republicans and others who said trying the men inside the United States would create security risks and allow the defendants legal protections that they shouldn't have.