An American citizen captured in Pakistan last year and flown to New York to face federal terrorism charges was hit with fresh allegations on Wednesday in connection with a 2009 attack on a U.S. military base in Afghanistan.

Federal prosecutors in Brooklyn obtained a superseding indictment against Muhanad Mahmoud al Farekh, 30, who was born in Texas and was once thought to be a top al-Qaeda operative. The CIA had been pushing to kill Farekh for more than a year before his arrest, current and former U.S. officials said.

The indictment charges Farekh with conspiracy to murder U.S. nationals, use of explosives, conspiracy to use a weapon of mass destruction and conspiracy to bomb a government facility.

The government accused Farekh of helping prepare a bomb to be used in the attack on Jan. 19, 2009. On that date, according to the indictment, two co-conspirators drove vehicles to the military base. The first detonated the bomb, which did not kill any U.S. military members, though a number of Afghan security forces were reported killed. The second drove a truck containing a bomb but did not set it off. Farekh’s fingerprints were recovered from packing tape on the unexploded bomb, according to the prosecutors.

The indictment also charges that between December 2006 and September 2009, Farekh provided material support to al-Qaeda.

“Farekh, a citizen of the United States, allegedly turned his back on our country and tried to kill U.S. soldiers in the course of executing their sworn duty to keep us safe,” said Robert L. Capers, U.S. attorney in Brooklyn.

The government alleged that in 2007, Farekh and two associates studying at the University of Manitoba in Canada traveled to Pakistan to link up with militants and fight against American forces. One of his associates, Ferid Imam, provided weapons and military-style training at an al-Qaeda training camp in Pakistan, including to three Americans who plotted to bomb the New York subway system. Two of the three have pleaded guilty and have yet to be sentenced, and the third was convicted and sentenced to life in prison. Imam has also been indicted for his role in the plot.

If convicted, Farekh faces a mandatory minimum sentence of seven years in prison and a maximum sentence of life imprisonment. He is due to be arraigned Thursday in federal court in the Eastern District of New York.