NEW YORK (AFP) — 4 New Yorkers arrested in an alleged plot to bomb a synagogue and shoot down military planes were indicted Tuesday on 8 charges, including attempts to use weapons of mass destruction.

The four, arrested May 20, 2009 in New York, face several life sentences if convicted, the federal prosecutor's office said.

They were indicted by a grand jury on charges of conspiracy and attempts to use weapons of mass destruction, to shoot down aircraft, and to kill US officers & employees, the indictment says.

3 of the men are US citizens, while the fourth is a Haitian immigrant.

The 4 were to be arraigned at court in White Plains, New York, on Wednesday.

Authorities say the suspects - David Williams, 28, James Cromitie, 55, Laguerre Payen, 27 and Onta Williams, 32,-- were caught in the act of attempting to blow up a synagogue and a Jewish center in NY.

They were allegedly planning to go on and fire an anti-aircraft missiles at military planes at a National Guard air base in Newburgh, NY state.

The bombs & missiles were duds supplied in an undercover FBI operation, prosecutors say.

NY police chief Raymond Kelly said after their arrest that they "stated they wanted to commit jihad," or Muslim holy war.

The drama came as debate intensified in Washington over President Barack Obama's plan to ban torture by US security forces and to shut down the controversial & secretive detention center at Guantanamo Bay, Cuba.

However, none of the 4 men is believed to have links to any external militant group and they were reported to have converted to Islam while incarcerated in United States prisons for other crimes.