U.S. and Iraqi forces on Thursday launched the largest air assault operation since the invasion of Iraq nearly three years ago, the U.S. military said.
More than 50 aircraft are involved in Operation Swarmer, supporting more than 1,500 Iraqi and U.S. troops near Samarra, about 75 miles (121 kilometers) north of Baghdad.
The aircraft also delivered troops from the Iraq and U.S. Army to "multiple objectives."
The offensive began Thursday morning in southern Salaheddin province "to clear a suspected insurgent operating area northeast of Samarra," the site of the bombing of the Shiite shrine that escalated sectarian tensions and pushed Iraq to the brink of civil war.
The death toll from apparent reprisal killings rose in Baghdad when Iraqi Emergency Police said they had found 31 bodies across the capital, 25 on Wednesday and another 6 on Thursday.
Since a string of car bombings in a poor Shiite neighborhood killed at least 46 people Sunday, police have reported finding the results of grisly execution-style slayings every day.
The latest discoveries came during a vehicle curfew in the capital.
More than 160 bodies have been recovered since Sunday, many found shot to death and some of which have shown signs of torture.
In northern Iraq, one person was killed and three injured in demonstrations marking the 18th anniversary of the gassing to death of thousands of Kurds in Halabja, police and hospital officials said.
Diyala province, north of Baghdad, continued to be a hotbed of violence.
In Khalis, a roadside bomb killed three girls and wounded five boys Thursday afternoon as students were leaving school, an official with Diyala's Provincial Joint Coordination Center said.
A roadside bomb in Muqtadya exploded near an Iraqi police patrol, wounding seven officers and one civilian, the official said.
In the provincial capital of Baquba, a gunmen killed one civilian and wounded another.
Iraq's newly elected parliament met for the first time Thursday and adjourned after only 30 minutes.
The lawmakers were sworn in amid tight security, but that was about all the new body was able to accomplish.
The meeting begins the 60-day countdown during which time a president, two vice presidents and a prime minister will be selected.