LOS ANGELES (AFP) - A gunman killed one person and wounded five others in a shooting spree in Arizona on Wednesday, sparking an ongoing manhunt by Swat teams, police said.

One of the injured was in critical condition after the shooting in Mesa, a suburb of Phoenix, said local police spokesman Esteban Flores.

"We have an active shooter situation," added Flores, who listed at least four locations where the gunman had opened fire, before fleeing in a carjacked vehicle.

Swat teams scrambled to look for the shooter, described as a white man in his 40s with a neck tattoo.

Local schools and colleges were placed on lockdown while police searched for the gunman.

The incident began when three people were shot at a motel. One male victim died while two women were hospitalised. Another male was shot at a nearby bistro, where a car was stolen.

A short time later police received reports of an attempted burglary nearby at which a male victim was shot, and another separate shooting at an apartment complex. A victim there was listed in critical condition, Flores said, about three hours after the first shooting.

"We don't know exactly what happened at the first shooting. We know there was some kind of argument," he said, adding: "The rest of them appeared to be carjackings or home invasions or some kinds of robberies."