Iraq's prime minister has gone on national television to appeal for calm after rival Shi'ite militias clashed in the Shi'ite holy city of Najaf killing at least five people and wounding several others.
Ibrahim al-Jaafari condemned the violence Wednesday that erupted when supporters of radical Shi'ite cleric Moqtada al-Sadr clashed with Shi'ite opponents as the cleric's backers attempted to reopen their Najaf office.
Some reports identify the other militia as the Badr Brigades, which is allied to Iraq's largest Shi'ite political party (the Supreme Council for the Islamic Revolution in Iraq or SCIRI).
Fighting was also reported among the two groups in Baghdad.
Moqtada al-Sadr's sympathizers in parliament say they will suspend their duties indefinitely in protest. That could complicate plans for the assembly to vote on the draft constitution Thursday.
Earlier Wednesday, at least 13 people were killed and more than 40 wounded after insurgents attacked several police checkpoints in western Baghdad.