Police spokesman Frank Robertson says there was an altercation around 10 pm (local time) yesterday during which a person produced a firearm and shot two people.
Robertson says one victim was struck in the neck and the other in the chest. He says both were taken to a local hospital.
Police said one suspect is in custody. No further details were immediately available.
The shooting occurred during the Muses parade the traditional kickoff to the Carnival weekend.
The city will host several parades daily until Mardi Gras, which is Tuesday.