On Sunday, the Republican chair of the Foreign Relations Committee, Sen. Richard Lugar of Indiana, said on ABC’s “This Week” that the U.S. may be forced to delay handing over power to Iraqis on June 30 and that the U.S. may be forced to send more troops to quell the violence.

Hints of the uprising that would start on Sunday emerged in the days prior.

On Saturday, 5,000 supporters of Sadr marched through East Baghdad protesting the U.S. for closing down the Al-Hawzah newspaper.

On Friday, the Miami Herald reported 20,000 Shiites protested outside the U.S. occupation headquarters in Baghdad, marking the largest protest there to date.

A sheikh representing Sadr told the crowd, “We fought Saddam, and now we’re fighting the Americans. Listen, America, Britain and Israel, there’s a man named Muqtada Sadr, and he gives resistance fighters their courage.”