BAGHDAD, Nov 28 (Reuters) - A female suicide bomber wearing an explosives blew herself up in a city north of Baghdad, wounding seven U.S. soldiers and five Iraqi civilians, the U.S. military said on Wednesday.

The attack occurred on Tuesday in Baquba, 65 km (40 miles) from Baghdad and capital of the ethnically and religiously mixed Diyala province.

Suicide bombings carried out by women are very rare in Iraq.

U.S. commanders have identified Diyala province as one of the most dangerous areas of Iraq after Sunni Islamist al Qaeda fighters were driven out of their former stronghold in the western province of Anbar.

On Tuesday, nine people were killed when a suicide bomber posing as a shepherd attacked the police headquarters in Baquba.

U.S. and Iraqi officials say attacks across Iraq have fallen by 55 percent since 30,000 extra U.S. troops that President George W. Bush sent to the country became fully deployed in mid-June.

The troop deployment is part of a security crackdown designed to avert civil war between Iraq's Shi'ite Muslim majority and the Sunni Arab minority, once dominant under Saddam Hussein.