Iraqi security forces have raided the home of a Sunni lawmaker, resulting in clashes that killed his brother and five of his guards.
Analysts say the arrest of Ahmed al-Alwani Saturday in western Anbar province is likely to inflame discontent among Iraq's minority Sunni community, compounding the rampant violence the country is experiencing.
It was not immediately clear on what charges Alwani was arrested. He is a well-known supporter of Sunni protests against Iraq's Shi'ite-led government.
Members of Alwani's guards and Iraqi security forces were wounded in the clash.
Unrest in Iraq has spiked since security forces stormed a Sunni protest camp north of Baghdad in April.
The violence this year has been the worst since 2008.