Streets in the Iraqi capital, Baghdad, are mostly quiet Friday, as security measures take effect on the eve of a nationwide constitutional referendum.
There were some sporadic incidents of violence, which killed four policemen and injured several Iraqis in Baquba, Kirkuk and Baghdad. Insurgents also bombed the Baghdad headquarters of the largest Sunni Arab political party and set fire to another of its offices outside the city.
It was in apparent retaliation for the Iraqi Islamic Party's decision to support the constitution.
A U.S. military spokesman Major General Rick Lynch said the number of attacks is down over the same period before the January parliamentary elections, but he said Iraqi and coalition forces remain vigilant.
Some six thousand polling centers will be open across Iraq Saturday for people to cast their vote for or against the new constitution.