Six members of the Iraqi security forces were killed just before dawn on Saturday when their control post in the village of Kubisa, 200 kilometres (125 miles) west of Baghdad, was attacked by armed raiders, a police spokesman said.
The men -- three soldiers and three police officers -- died in the attack at 5am (0200 GMT).
Eight other people, including four civilians, were injured in the attack in Al-Anbar province.
None of the gunmen was killed or captured.
Al-Anbar, which covers Iraq's western desert, is a former stronghold of the Sunni Arab rebellion.
Violence in the province had begun to tail off after tribal chiefs, weary of al-Qaeda attacks and backed financially by the US, rose up against the extremists in September 2006, forming militia dubbed "Sahwa", or Awakening.