New Orleans officials offered stern warnings Tuesday about cluttering the neutral grounds along Mardi Gras parade routes this year, saying they won't allow tents anymore and will send out crews to remove ladders and other items that have been set up too far in advance of parade day.

The ban on enclosed tents appears to be new, prompted by an incident last year in which someone accidentally discharged a gun inside a portable toilet.

The city code appears to allow tents along parade routes, requiring only that "ladders, tents, grills and other personal effects" must be set back 6 feet from the curb.

But Mayor Mitch Landrieu's administration has decided that tents with walls, as opposed to open-sided canopies, constitute a "barricade" that might "obstruct passage along public property," something that's prohibited.

“This is a homeland security threat,” Landrieu said. “We need to be able to see. There can be tarps, but there can be no tents.”

Police said last year that a man appeared to have unintentionally discharged a weapon inside a toilet during the Krewe of Tucks parade, injuring a 36-year-old man from Metairie.

The first big parading weekend of Carnival begins Friday, with 15 riding or walking parades scheduled to roll in processions that are likely to give nods to the city’s 300th birthday.

Other rules bar setting personal items along the parade route more than a day ahead of a parade and bringing weapons to parades.

The latter prohibition will be monitored by way of a high-tech, real-time camera system that was unveiled this year.

A host of cameras, some of which will flash blue and red, will be recording activity along the Uptown, Mid-City and West Bank parade routes.

When asked how the new cameras would deter crime in areas out of their line of sight, Landrieu and city Homeland Security and Emergency Preparedness Director Aaron Miller touted other, less obvious cameras, as well as a host of plainclothes law enforcement officials.

“You can assume that if you are on the parade route, you are being watched,” Landrieu said.

At least 165 State Police troopers will be in town assisting the New Orleans Police Department by Feb. 9, Trooper Melissa Matey said.

In addition, officers from Tulane University, the St. John the Baptist Parish and Jefferson Parish Sheriff’s Offices and other police departments will be on hand.

NOPD officers will go to 12-hour shifts starting this Friday, Superintendent Michael Harrison said.

Most parades on the traditional Uptown route will alter their routes slightly in another bid for safety. Instead of taking a left turn toward the lake on Canal Street from St. Charles Avenue before making a U-turn back toward the river on the other side of Canal, krewes will simply turn right onto Canal toward Convention Center Boulevard. The aim is to let police keep lakebound traffic flowing in case of emergency.

As they often have before, Landrieu, Mayor-elect LaToya Cantrell and other officials urged parade-goers to be mindful of criminal or suspicious activity, and to report something if they see it.

Officials reminded people that the city code prohibits putting ladders, chairs and other items on parade routes to save a spot earlier than 24 hours before the start of a parade.

In the past, that rule has never stopped hundreds or thousands of people from leaving those items along parade routes days ahead of time, particularly for the superkrewe Endymion.

But city crews were out Tuesday collecting and disposing of those items, and they will continue to do so until a day ahead of parades, Department of Parks and Parkways Director Ann Macdonald said.

Follow Jessica Williams on Twitter, @jwilliamsNOLA​.