Police say an Iraqi army captain was killed Monday when a bomb planted on his car exploded in the city of Fallujah, west of the capital.

The attack comes less than a month after Iraqi forces assumed responsibility for security in Iraq's cities and U.S. combat troops pulled out of urban centers.

Iraqi authorities say a Sunni tribal chief was killed in a similar bomb attack Monday in the northern city of Mosul.  Elsewhere in Mosul, police say a roadside bomb wounded six members of Iraq's security forces while they were on patrol.

The U.S. military in Iraq says two members of Iraq's Special Operations Forces were killed by gunfire during an operation near Baghdad Monday.  The insurgent who opened fire was wounded in the ensuing gunbattle and captured.

U.S. troops, acting as advisors, were working with the Iraqi soldiers in the combined operation, in accordance with the U.S. - Iraqi security agreement.

And, in eastern Baghdad Monday, a roadside bomb killed one civilian and wounded four others on Palestine Street.

Although overall violence has declined in Iraq, there have been multiple deadly attacks in Iraqi cities in the weeks leading up to, and following, the June 30 withdrawal of U.S. combat troops from urban areas.