Police are asking residents on Calle Arboleda and Alameda del Prado to remain inside until the investigation is complete.
Police confirmed to ABC7 Eyewitness News that at least one person was injured, but it was not immediately clear who was hurt or whether the gunman had been apprehended.
The scene appears to be outside an apartment complex.
Southbound Alameda Del Prado at Ignacio Boulevard is closed, and police are asking drivers and residents to avoid the area. Authorities have not said how long the road closure will remain in effect.
Additional information was not immediately available as the investigation continued.