Meanwhile, Car bombs and a suicide blast hit Shi'ite districts of Baghdad and south of Iraq's capital, killing at least 50 people on the 10th anniversary of the invasion that ousted Saddam Hussein. Sunni Islamist insurgents tied to al Qaeda have stepped up attacks on Shi'ite targets since the start of the year in a campaign to stoke sectarian tension and undermine Prime Minister Nuri al-Maliki's government.