(Adds security source comment in paragraph 3) By Alaa Shahine BAGHDAD, Dec 7 (Reuters) - A woman wearing a vest packed with explosives killed 16 people and a suicide car bomb killed 10 in Iraq on Friday, in attacks aimed at units helping U.S. forces fight al Qaeda. Police said 27 people were wounded in the first attack, when the female suicide bomber struck at former Sunni Arab insurgents who have switched sides to join U.S.-backed security forces battling al Qaeda. A security source said the female bomber had three adult children who had been killed in operations by Iraqi forces. The car bomb killed seven Iraqi troops and three members of a local neighbourhood patrol. Eight people were hurt. Both strikes took place in religiously and ethnically mixed Diyala, Iraq's most violent province, where U.S. forces say al Qaeda gunmen are regrouping after being pushed from other areas. Police said the female bomber targeted a building used by members of the 1920 Revolutionary Brigades in the town of Muqdadiya, 90 km (55 miles) northeast of Baghdad. The Brigades were once one of the main groups of Sunni Arab insurgents fighting U.S. forces and the Shi'ite-led government, but in recent months many members have begun working alongside security forces against Sunni Islamist al Qaeda. Witnesses said a woman walked up to the building, in a street full of shops, and began asking questions. She detonated the vest she was wearing when people out shopping before Friday prayers began gathering around her. "We saw several bodies. It is Friday and the area was crowded," Ammar Fadhel, a 35-year-old labourer, told Reuters. The U.S. military put the death toll at 12, with 18 wounded. All were civilians, it said in an email to Reuters. Police put the toll at 16 and said women and children were among the casualties. In the second attack, a suicide car bomber struck a checkpoint in the village of Dali Abbas which, like Muqdadiya, is just north of Diyala's provincial capital Baquba. A build-up of 30,000 extra U.S. troops this year and the rise of neighbourhood security patrols organised by mainly Sunni Arab sheikhs have helped reduce violence in Iraq. U.S. forces say the security crackdown has squeezed al Qaeda out of former strongholds like western Anbar province into other areas north of Baghdad like Diyala, making the north the new focus of the fight against al Qaeda. At least 61 people have been killed and about 90 wounded in Diyala province in the past week in five major bombing and shooting attacks. While overall U.S. troop numbers have started to fall in Iraq, force levels are increasing in Diyala. DRIVE-BY SHOOTING Attacks on the neighbourhood patrols have increased as the units spread throughout Iraq. On Thursday, four patrol leaders were killed by unidentified gunmen in a drive-by shooting in the town of Rabia in northwest Iraq, police said. U.S. forces pay about 50,000 people $10 a day to patrol neighbourhoods and man checkpoints in the units, with about 10,000 more working as unpaid volunteers. The Iraqi government said this week it would begin taking over the programme, putting most of the patrols on its payroll by mid-2008. Attacks have fallen 55 percent in Iraq since the troop build-up was fully deployed in mid-June, but General David Petraeus, commander of U.S. forces in Iraq, has said al Qaeda remains a dangerous foe, especially in the north. An al Qaeda-linked militant group issued a threat earlier this week vowing a wave of attacks on Iraqi security forces. Also in the north, militants bombed an oil pipeline used in Iraq's domestic supply. Authorities said a fire was being controlled and would not hurt exports or refineries. Still, other parts of the country have become far quieter in recent months, and ordinary life is slowly reviving in Baghdad. A mass wedding was held in a Baghdad hotel on Friday, allowing scores of couples previously prevented from marrying by insecurity to tie the knot at last. "The main dream of every girl is her wedding day," said a bride dancing with her groom at the event, shown on national television. "Today I can have my dream after such long suffering." Suicide bombings by women are rare in Iraq. An attack by a female suicide bomber wounded seven U.S. soldiers and five Iraqi civilians on Nov. 27 in Baquba. (Writing by Paul Tait and Peter Graff; editing by Andrew Roche)
