ISI is the umbrella group of Sunni jihadis to which various organizations, including Al Qaeda in Iraq, have pledged their allegiance.

I’m on my way out the door, but here’s the article. Big fish on the hook here if it’s true.

Update: More background on ISI from Roggio:

Al-Qaeda established the Islamic State in Iraq in October of 2006 to put an Iraqi face on al-Qaeda’s operations in Iraq and unite the Sunni disparate elements of the insurgency. Al-Qaeda claims the Islamic State of Iraq is comprised of “Baghdad, Anbar, Diyala, Kirkuk, Salah al-Din, Ninawa, and in other parts of the governorate of Babel.” The declaration of the Sunni Islamic State of Iraq followed the creation of the “Mutayibeen Coalition,” which includes six Anbar tribes, as well as three smaller insurgent groups.

But not all Sunni insurgent groups have united under the banner of al-Qaeda’s Islamic State. Sunni tribes and elements of insurgent groups such as the 1920s Revolution Brigade and the Islamic Army in Iraq in Anbar province have formed the Anbar Salvation Council and have fought pitched battles against al-Qaeda, the most recent in Amiriya.