Police are trying to figure out what sparked a gun battle in a New Orleans park that left 16 people wounded.

Hundreds of people were gathered late Sunday for what police have described as a combination block party and music video shoot.

Then two groups of gunmen pulled out weapons and started shooting at each other. In the chaotic aftermath, the gunmen ran off.

Police spokesman Tyler Gamble says all the victims were in stable condition and either suffered direct gunshot wounds or were grazed by bullets.

New Orleans Mayor Mitch Landrieu is calling on people with knowledge of the incident to help police.