Woman with bomb kills 6

BAGHDAD, Iraq (CNN) -- A woman suicide bomber set off a blast on Wednesday in an outdoor market in Iraq's Diyala province, killing six civilians and wounding seven, authorities said.

The attack took place in Khan Bani Saad, northeast of Baghdad.

It was the fourth such suicide strike carried out by women in the province over the last three months, said Col. Ragheb al-Aumairi, the spokesman of Diyala military operations headquarters.

Also in Diyala, coalition troops on Wednesday killed three suspected militants in an operation west of Muqdadiya. Two people were detained in that raid, and raids in Baghdad and Mosul resulted in the detention of one person each.

U.S. soldiers and Iraqi security forces have been engaged in military operations in Diyala province, where militants have established a strong presence.

While fighting in the region has been constant during the nearly five-year-old Iraq war, there has been a focus on Diyala and other northern Iraqi provinces during the U.S. military troop increase.

In the northern province of Salaheddin, three U.S. soldiers from Multi-National Division-North were killed by small arms fire on Wednesday, the U.S. military said. Two other soldiers were wounded in the incident, according to the military.

The deaths put the number of U.S. military personnel to die in the Iraq war at 3,926. The total for January is 22 -- 16 of whom were from Multi-National Division-North, the military said.

The U.S. military said Wednesday that a suspected militant killed during a December 30 operation near Muqdadiya in Diyala province has been positively identified as one of the key al Qaeda in Iraq leaders operating there.

Abu Layla al-Suri, also known as Abu Abd al Rahman, "has been intricately involved in the terrorist network operating in the Diyala River Valley region since October 2006, and was closely associated with several al Qaeda in Iraq senior leaders."

Farther south in Baghdad, three people died in roadside bombs, the Interior Ministry said.

One bomb exploded near an Iraqi police patrol in a commercial district in Baghdad. That attack killed two civilians and wounded four others, an official with the Interior Ministry said. Another in southeastern Baghdad killed one civilian and wounded four others, the ministry said.

Three mortar rounds landed Tuesday night in Baghdad's Green Zone, where U.S. and many Iraqi government offices are located. There were no further details about damage or casualties.

A vehicle curfew will be among stiff security measures imposed in some Iraqi regions at the end of the week as Shiites mark an annual religious commemoration, the Iraqi Interior Ministry said.

The Ashura festival commemorates the death of Imam Hussein, the grandson of Prophet Mohammed and the third imam of Shiite Islam. He died in battle in the 7th century.

No vehicles will be allowed on the streets from 8 p.m. Thursday until 6 p.m. Saturday to cover the peak period of the commemoration.

Pilgrims are streaming to Shiite shrine cities such as Najaf and Karbala and to Baghdad's Kadhimiya district to mark the commemoration. During Ashura, processions of Shiites remember Hussein's martyrdom by self-flagellation and displays of grief.

Violence in Iraq has dropped, but security forces are vigilant about a re-emergence of Sunni-Shiite sectarian strife. There has been bloodshed during Ashura in the post-Saddam Hussein era; in 2004, attackers killed more than 180 people in Karbala and Baghdad.

Security has been being beefed up and vehicle curfews are being imposed in Baghdad, Diyala province and the Shiite heartland in southern Iraq. E-mail to a friend

CNN's Mohammed Tawfeeq contributed to this report.

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