WASHINGTON, March 31: The US government has made unprecedented security arrangements for the jurors deciding the fate of convicted Al Qaeda operative Zacarias Moussaoui, officials said.

The jury of nine men and three women held their first full day of deliberations on Thursday to decide whether Zacarias Moussaoui should get the death penalty, but they are not being sequestered.

The jurors have been protected by a large force of heavily armed US marshals under tight security modelled after precautions taken in high-profile terrorism trials in New York a decade ago, sources said.

The Moussaoui case jurors know their identities are to remain concealed but have not been informed of the distant possibility that Al Qaeda could seek retribution if they vote for Moussaoui’s death, the sources said. Marshals pick up jurors at an undisclosed rendezvous point every morning and transport them to the Alexandria, Virginia, court.

They are often seen entering the courthouse in single file between cordons of blue blazers - marshals who usher them into an express elevator to the seventh-floor court. Outside, Homeland Security and Alexandria police carrying rifles scan for threats along with rooftop snipers.

Moussaoui, 37, pleaded guilty to six counts of conspiracy last year in connection with the 9/11 attacks.