The claim of contact from "several insurgent groups" trying to negotiate an amnesty is not impossible, but under the circumstances appears more likely to be false or mostly false, than true or mostly true.
A credible offer of amnesty would have to include a credible offer of protection. The people currently calling themselves the Iraqi government can't even manage to protect their own families from assassination and kidnapping.
Given the lengthy build up to this latest Fallujah episode, I suspect that most of the combatants who intended to get out of the city are already long gone to other areas. Though I suppose that civilians could try to save themselves by "surrendering", if offered the opportunity.
What I'm wondering right now is whether another "brokered solution" is in the offing, and whether this story is meant to set the stage for it. If you'll recall, back in April during the first big assault on Fallujah, the press reporting followed the same pattern:
- The build up to the attack was widely reported in the press
- The attack was announced with much fanfare
- A significant number of casualties were incurred over a short period of time, and the news of this was relatively underplayed
- There was an abrupt scarcity of new stories about the events unfolding in Fallujah
- After the pause in coverage, new stories were released that suggested that an agreement had been reached between the resistance fighters and the forces of the Iraqi interim government, whereby the latter would assume control of the situation, allowing the Americans to withdraw.
Is that what's happening here as well? I simply don't know. The reality could be something similar to that, or something completely different. Whatever the case, it's interesting to think about, and your guess is as good as mine.