Suicide attackers detonated a pair of car bombs outside an Iraqi National Guard (search) compound west of the capital on Sunday, wounding American and Iraqi forces, a U.S. military official said.

The two militants, who died in the blasts, tried to ram the cars into the base located in Kharma, a town on the outskirts of the insurgent stronghold of Fallujah (search), said the official, who spoke on condition of anonymity.

The number of U.S. and Iraqi casualties was not immediately clear.

Insurgents have targeted Iraqi security forces because they are seen as collaborators with the Americans and their allies in the interim government.

American troops have staged repeated attacks in Fallujah on sites that the U.S. military describes as being used by followers of Jordanian-born terror mastermind Abu Musab al-Zarqawi (search).

But U.S. troops have not entered Fallujah since the end of a three-week siege in April that killed hundreds.