NEW ORLEANS -- The Coast Guard closed all ports from New Orleans to the Florida Panhandle ahead of the arrival of Hurricane Katrina early Monday.

The Coast Guard had set Hurricane Condition X-Ray, or Condition Three, for affected ports Saturday, meaning the ports were open for departing vessels, but no vessels were allowed to come into port with the exception of inland barge traffic.

The Coast Guard expected to close all ports to traffic no later than 2 a.m. Monday.

The huge storm, packing 160 mph winds, is expected to hit the northern Gulf Coast as a Category 4 or 5 hurricane Monday morning. An estimated million residents had fled the city under a mandatory evacuation order.

All ocean-going, commercial vessels and ocean-going barges greater than 200 gross tons not approved to remain in port were ordered out prior to the setting of Condition Yankee, or Condition Two, at 2 p.m. Sunday. None of these vessels are permitted to anchor within territorial waters.

Barge fleets have been ordered to reduce their fleets as much as possible and begin to shift unloaded barges to appropriate safe shelter.

A container vessel departed the Pot of New Orleans Saturday night after loading at the Napoleon Avenue wharf.

All cranes at the Port of New Orleans have been locked down, and the Mississippi River below New Orleans is closed to all river traffic.

By Janet Plume