The latest attack came as funerals were held in Baghdad for 90 people killed when suicide bombers attacked the city's Baratha mosque, an important place for Shiites.
For the first time, a senior Iraqi government official has said Iraq in a state of undeclared civil war.
Deputy Interior Minister Hussein Ali Kamal said the country had been embroiled in a civil war for the past 12 months.
Shiite leader Abdel Aziz al-Hakim has warned against reprisals against Sunnis and called on the country's Sunnis to help unify Iraq.
Egyptian President Hosni Mubarak has expressed fears the violence could spread beyond Iraq's borders and engulf the entire region.