Yemeni al-Qaeda militants hold a black al-Qaeda flag as they are sentenced for plotting attacks in Yemen at a court in Sanaa.

Two Yemeni nationals were charged in the United States with conspiring to murder Americans abroad and providing material support to al Qaeda, according to a complaint and arrest warrant unsealed on Tuesday.

Saddiq Al-Abbadi and Ali Alvi were arrested in Saudi Arabia and expelled to the United States, the U.S. Justice Department said. Alvi appeared in a federal court in Brooklyn on Sunday and Al-Abbadi was scheduled to be arraigned Tuesday afternoon, thedepartment said.

The two Yemenis engaged in attacks against U.S. military forces in Afghanistan in the summer of 2008 and had traveled in March of that year to Pakistan to train and fight with al Qaeda, prosecutors said in the complaint.

The pair also helped an American citizen join al Qaeda, according to the complaint.

Originally filed under seal in April 2009, the complaint describes a cooperating witness who traveled to Pakistan in 2007 with the intention of “waging violent jihad” against the United States, and who was able to join al Qaeda in Pakistan with the help of Al-Abbadi and Alvi.

The witness, who previously pleaded guilty to conspiring to murder Americans abroad, providing material support to al Qaeda, and receiving military-type training from the group, told prosecutors of training in Pakistan’s tribal areas in a basic weapons course and advancing to explosives and projectile weapons training, according to the complaint.

The complaint also alleges that a second confidential source who traveled from Saudi Arabia to Iran and then to Pakistan corroborated information about the two Yemeni defendants.

[wpResize]