First of all, this is not "insurgents." This is an al Qaeda operation, as should have been obvious by the choice of targets. Al Qaeda is currently attacking Sunnis in the Anbar area that are rising up against them. The words "al Qaeda" don't even appear in your linked article.

The second attack in Amiriya targeted a tribal leader opposed to al Qaeda.

The third attack was in the Albu Issa region of Fallujah, where the local tribe has been supporting the Iraqi government and the Coalition. There was an attack on March 1st by al Qaeda in this same area against a leader of the Anbar Salvation Council, a group of Sunni Anbar tribes (25 out of 31) aligned against al Qaeda.