A suicide bomber today drove a car bomb into a police station in a town north of Baghdad.
The attack in Hibhib killed 13 people and wounded 15, police said.
Earlier, the US military said two soldiers were killed south of Baghdad, and ten were wounded in an attack earlier this week.
The attack on Tuesday - described as indirect fire, which refers to rockets or mortars - brings the total of US troops killed in July to 80.
It was the least deadly month for US forces since last November.
The US military has hailed the reduction in deaths among its forces as a sign that this year's strategy of sending additional troops to Iraq and spreading them into neighbourhoods in Baghdad and other cities is improving security.
In each of the last three months, the death toll among US troops was more than 100, making the April-June period the deadliest quarter-year of the war, however.
However, Iraqi government figures released yesterday showed a sharp rise in the number of Iraqi civilians killed in July to 1,653 from 1,227 in June.