BAGHDAD — 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 today.

More Iraqi refugees, heartened by reports of the lull in violence in Baghdad, were beginning to return and today a convoy of more than 800 people was expected in the Iraqi capital after an overnight bus ride from Damascus, Syria. A government spokesman said that 60,000 Iraqis had returned in the past month.

“The Iraqi government will do its best to protect these families,” the spokesman, Ali al-Dabbagh, said at a news conference today.

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 Tuesday after the vehicle tried to go through a roadblock, killing at least two people on board.

And today, 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.

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 they tried to reach the building.

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

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

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 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 today.

, detaining suspects in Tikrit and Kirkuk as well as the Iraqi capital.