NEW ORLEANS -- An infant and at least six other people were shot Tuesday along a parade route packed with Mardi Gras revelers, police said.

Police arrested Mark Brooks, 19, and Louis Lazone, 18, both of New Orleans. They were charged with seven counts each of attempted first-degree murder, police said.

Emergency officials initially reported that six people were shot, but New Orleans police spokesman Garry Flot said in a news release Tuesday evening that seven people were injured. They include three men ages 50, 33, and 20; two women ages 17 and 20; a 15-year-old boy and a 20-month-old boy.

The victims' injuries are not life-threatening; their conditions ranged from guarded to stable, New Orleans EMS spokesman Jeb Tate said.

New Orleans police spokesman Bob Young said at least some of the victims appeared to be innocent bystanders. He said one of the victims was a woman watching the parades from atop a ladder.

The shootings happened along a busy stretch of the parade route uptown, while truck parades rolled after Rex -- the city's signature Mardi Gras parade -- on Tuesday afternoon.

"We were here watching the parade. I heard the shots. I thought it was fireworks," said witness Sam Stiltner. "I turned around and everybody was running."

Young said several New Orleans police officers were nearby when the shootings happened, so officers were able to quickly make arrests. Officers also recovered three guns at the scene, Young said.

Even with two people in custody, Stiltner said the weight of the shooting on Fat Tuesday is too much to bear.

"I have not been down here in 22 years," Stiltner said. "I ain't coming back. This was supposed to be the safe area, but it ain't safe."

Recession? Mardi Gras Revelers Party On

The national recession did not keep visitors away from Mardi Gras, as the 100th anniversary Zulu parade led off a celebration Tuesday that will put the exclamation point on this year's Carnival season.

Cool, clear conditions brought hundreds of thousands of revelers to the streets in the early hours of the day.

Zulu rolled on time and smoothly along its traditional route. It will be followed by the world's most famous Mardi Gras parade, Rex, parading under the theme "Spirits of Spring."

Parades in Metairie, the Westbank and the Northshore also drew huge crowds Tuesday.

It was Zulu that got the festivities going with its 8 a.m. start.

New Orleans Mayor Ray Nagin helped lead the parade through Uptown, riding a horse and costumed as a "Recovery Gladiator."

"It's a wonderful day out here. The crowds are spectacular, and we're just having a good time," Nagin said.

The mayor told TV station WDSU he chose the theme to salute all New Orleanians helping lead the city back from Hurricane Katrina.

"The city of New Orleans, the people, have gone through so much. I just wanted to represent the 'fighting spirit' we have to save this city," Nagin said. "If you want me to be a gladiator today, Spartan, a Roman soldier -- I just want to represent the fighting spirit of this city."

With crowds heavy by even pre-Katrina standards, Mardi Gras 2009 seemed to mark yet another sign of the city's continued recovery.

"About 75 percent of our citizens are back," Nagin said. "There's more construction going on in this city than in most other cities around the country. You know, they say there's a national recession around the country, but if you come to New Orleans, you don't really see it."

Tourism officials say it appears the national recession did not keep visitors away. Hotels and restaurants have reported brisk business this Carnival season, with some hotels at full occupancy.

Music legend Pete Fountain returned to Mardi Gras, leading his "Half-Fast Walking Club" on its annual march.

In addition to the more traditional parades, four truck parades were also scheduled to roll: two in New Orleans, two in Metairie.

On Bourbon Street, many Monday night revelers could still be found greeting Mardi Gras dawn. Police reported no major problems Monday night or Tuesday morning.