Insurgents battled police and troops west and north of Baghdad.
In Anbar province west of the capital, militants attacked two police stations and a local official's house in the towns of Rawa and Aana near the main highway from Baghdad to the Syrian border, killing seven police and the official's brother, medical and security sources said.
Deputy Interior Minister Adnan al-Assadi told journalists a large group of militants had attacked Aana, seeking to take control of security force positions.
North of Baghdad, two soldiers and four militants died in clashes in the Hamreen area, officers said.
A helicopter pilot was wounded by gunfire in the operation, during which two militants were arrested and weapons seized, army Staff Lieutenant General Abdulamir al-Zaidi told AFP.
Two officers said a helicopter had been shot down, but Zaidi insisted that it was able to return to base.
Three people were killed in the northern province of Nineveh and two in Babil province, south of Baghdad.
The UN refugee agency said it was "increasingly concerned about the situation in Iraq, where recent waves of sectarian violence threaten to spark new internal displacement of Iraqis fleeing bombings and other attacks."
This year, "bombings and rising sectarian tensions have displaced some 5,000 Iraqis, with people mostly fleeing from Baghdad into Anbar and Salaheddin governorates, as well as causing displacement within Diyala and Nineveh governorates," agency spokeswoman Melissa Fleming said in a statement.
There are already "more than 1.13 million internally displaced people... Inside Iraq who fled their homes to escape intense sectarian violence from 2006-2008," she added.
