A wave of violence has hit Iraqi towns where support for Saddam Hussein is highest. There have been several attacks on U.S. troops and a series of unruly protests in support of the captured Iraqi leader.

In the most serious incident, the U.S. military says troops in the town of Samarra, north of Baghdad, killed 11 insurgents who tried to ambush their convoy. No U.S. soldiers were injured in that incident.

But U.S. military and journalists in Saddam's hometown of Tikrit say at least three soldiers were wounded when a roadside bomb exploded near their convoy Tuesday.

Saddam was captured near Tikrit on Saturday, where residents have since taken to the streets in large numbers to protest his arrest. On Monday night, Saddam supporters rioted in the flashpoint towns of Fallujah and Ramadi, west of Baghdad.

A military statement says U.S. troops were shot at repeatedly in Ramadi during a chaotic protest by about 700 people. They returned fire, killing two Iraqis and wounding two others. Two U.S. soldiers were also wounded in the incident.

In Fallujah, troops killed two more Iraqis after a rampaging crowd of angry Saddam supporters stormed the regional government offices and forced Iraqi police to flee.

Military officials say they expected an upsurge in violence in the wake of Saddam Hussein's capture. They say the unrest seems to be a combination of popular sentiment in pro-Saddam towns and orchestrated attacks by insurgents.