Officials say a roadside bomb has killed the governor and police chief of Iraq's southern Diwaniyah province.

The bomb Saturday struck a convoy carrying Governor Khalil Jalil Hamza and police chief Khalid Hassan, killing the two men and at least two members of their security staff.

Police say the attack occurred as the men were returning to the provincial capital of Diwaniyah from a funeral service for a tribal sheik.

The Diwaniyah region has seen a rise in internal rivalries between Shiite militias. It is also the site of frequent clashes between the militias and U.S.-led security forces.

In separate news, U.S. Attorney General Alberto Gonzales arrived in Baghdad today to meet with U.S. justice employees working in Iraq.

In a statement issued by the Justice Department, Gonzales praised the efforts of justice workers to improve the country's law enforcement and legal systems.

Gonzales also met with the top U.S. commander in Iraq, General David Petraeus, and plans to meet with ambassador Ryan Crocker.

In violence Friday, a car bomb exploded at a market in a predominantly Kurdish area of the northern city of Kirkuk, killing 11 people.

Some information for this report was provided by AFP, AP and Reuters.