BAGHDAD (AP) – A woman wearing an explosives belt blew herself up near an American patrol northeast of Baghdad, a rare female suicide bombing that wounded seven U.S. troops and five Iraqis, the U.S. military said Wednesday.

More Iraqi refugees, heartened by reports of the lull in violence in Baghdad, were beginning to return and on Wednesday a convoy of over 800 people was expected in the Iraqi capital after an overnight bus ride from Damascus, Syria.

Khaled Ibrahim, 45, from central Baghdad, said Tuesday he was so homesick after having been away for a year, that he wanted to give it a try after hearing things in Iraq have improved. “If I go and discover that the situation is not stable I will come back” to Syria, said Ibrahim, with his wife, three sons and two daughters in tow.

But tensions, and security concerns, remained in Baghdad. American troops fired on a minibus carrying bank employees on their way to work on Tuesday after the vehicle tried to go through a roadblock, killing at least two people on board. And on Wednesday, Iraqi lawmakers briefly boycotted the start of a legislative session, demanding that U.S. forces ease checkpoint searches as they try to enter the fortified Green Zone, where the parliament building is located.

Firyad Rawndouzi, spokesman for the Kurdish bloc, said the boycott came in response to “the insulting behavior of the American soldiers toward parliament members” as the tried to reach the building.

The U.S. military says attacks across Iraq have fallen to their lowest level since February 2006, attributing this partly to a surge of nearly 30,000 troops earlier this year.

A statement said the Diyala attack happened Tuesday near the provincial capital Baqouba, 35 miles northeast of Baghdad, when the woman detonated her explosives belt.

An Iraqi army officer in Diyala said Tuesday that a female suicide bomber targeted a U.S. patrol near Baqouba, wounding five Iraqi civilians. The officer, who spoke on condition of anonymity because he was not authorized to share the information with the media, did not know at the time if there were U.S. casualties.

Attacks by women in Iraq are believed to be rare but not unprecedented.

In April 2006, one of four suicide bombers who attacked a Shiite mosque in Baghdad was wearing a woman’s abaya veil, U.S. officials said. And in November 2005, a 38-year-old Belgian convert to Islam, Muriel Degauque, blew herself up trying to attack U.S. troops, but she was the only one killed, U.S. officials said.

With the lull in violence in Baghdad, American and Iraqi forces conducted sweeps against al-Qaida outside the capital, the U.S. military said Wednesday, detaining suspects in Tikrit and Kirkuk as well as the Iraqi capital.