Who are the men breaking into Zeitoun's house? What are they wearing? What weapons are

The armed men who burst in (who are, in fact, six men and one woman) seem to be law enforcement officers, and they promptly arrest everyone in the house as well as Todd Gambino, who arrives just as they are about to leave with the prisoners. Initially, the men think they are being forcibly evacuated as Mayor Nagin recently ordered all those in New Orleans to leave, but it becomes clear that their situation is more dire when they are detained at a bus station converted to a makeshift prison.