Attacks on the Green Zone increased in the wake of Iraqi military operations in Basra. The Green Zone houses the offices of Iraqi and U.S. governmental officials and several other departments.

U.S. officials said their military operations in Sadr City, the stronghold of Shiite cleric Moqtada Sadr, targeted the "special groups" allegedly backed by Iran that target the heavily fortified region in Baghdad, The Washington Post reported Thursday.

"We accomplished what we were trying to do, which was to stop the indirect fire," said the chief of staff for Multi-National Division-Baghdad, Col. Allen Batschelet.

Statistics provided by the U.S. military show that of the 697 rockets and mortar rounds fired from Sadr City since March 23, 292 struck U.S.-led forces and 113 fell inside the walls of the Green Zone.

U.S. officials noted the patience expressed by Sadr's militia, the Mahdi Army, in avoiding "future escalations of violence" and blamed the "special groups" for nearly 73 percent of the recent attacks.

Batschelet said that activity "has pretty much stopped."