When that explosion was heard, a group of Iraqi civilians, who were nearby, gathered at the site of the aftermath [and] were watching what was going on.
And when they apparently realized that this was an attack on a U.S. military force, they erupted in cheers. And that cheering went on for several minutes.
Just to confirm Tresy's analysis.
UPDATE: Alert reader santoast chastises me for using "frat boy" as a term of abuse. And... santoast is right. Headline changed to "Pretzel Boy"— as in the old ads where the catchline was, "Prove it, Pretzel Boy." Also, of course, for the subliminal Steely Dan reference.