[JURIST] The Chief of the US Army National Guard Bureau [official website] said Thursday in Washington that the National Guard was deploying over 4000 military police to support civilian law enforcement officers around New Orleans and elsewhere in the aftermath of Hurricane Katrina. "This is not martial law," said Lt. Gen. H Steven Blum [official profile], referring to some erroneous media reports. "This is helping a police force that is overstretched with the extraordinary challenge that it’s facing." Despite its use by local officials, most recently the mayor of New Orleans [JURIST report] on Wednesday, "martial law" – technically, emergency government by military authorities – is not recognized in Louisiana state law [JURIST report], according to a clarifying statement issued Tuesday by the Louisiana Attorney General's office. Assistant Secretary of Defense Paul McHale similarly insisted that all law enforcement would be on the National Guard side operating under control of state governors; some 7000 active duty federal troops would also be involved in rescue and recovery operations, but federal law in the form of the Posse Comitatus Act [Wikipedia backgrounder] prohibits them from conducting domestic law enforcement. The American Forces Press Service has more; the New Orleans Times-Picayune provides additional coverage.

National Guard Bureau historian Renee Hylton meanwhile told the Navy Times Thursday, "The Guard has been sent in many times to maintain law and order. But just to maintain law and order is not automatically martial law.” "'Ruled by military’ is not part of the British-American tradition", she explained. Actual impositions of martial law within the United States are rare; in recent times, the governor of Indiana declared martial law during a labor strike in the 1950s and Phenix City, Alabama was made subject to a similar declaration around the same time as part of an effort to tackle organized crime. The Navy Times has more.

8:50 PM ET – The security and law enforcement situation in New Orleans continues to deteriorate. The current headline on the New Orleans WWL-TV website is a a single word: "Anarchy".

9:55 PM ET – In a late Baton Rouge press conference Thursday, Governor Kathleen Blanco said she was sending 300 heavily-armed Arkansas National Guard troops just back from Iraq into New Orleans to help restore order: "They have M-16s and they are locked and loaded. These troops know how to shoot to kill…and I expect they will."