By David Schwartz

PHOENIX (Reuters) - A man apparently angry over a divorce case went on a shooting spree in and around Yuma, Arizona, on Thursday, killing five people and wounding another before taking his own life, authorities said.

One of the dead was identified as attorney Jerrold Shelley, who was shot inside his downtown law office, Yuma Police Chief Jerry Geier told Reuters by telephone.

The gunman, identified as Carey Hal Dyess, 73, also knew the other victims, Geier said, but their names were not immediately released. All of the dead appeared to be adults, he said.

Details of the incident were sketchy, but police said the shootings unfolded over several hours at six different locations in and around the city, located in the southwestern corner of Arizona near the border with Mexico.

Yuma Mayor Alan Krieger said the gunman's motive was not entirely clear, but that he was believed to be upset over a divorce case.

The first shooting occurred at about 5 a.m. local time in a rural area outside Yuma, authorities said. The gunman then drove in a rented car to several other rural locations to shoot other people before driving to Shelley's Yuma law office, where he opened fire on the attorney, Geier said.

Sheriff's deputies found Dyess dead from an apparently self-inflicted gunshot wound shortly before 11 a.m. -- about 90 minutes after Shelley was gunned down -- just off a highway in a rural area outside Yuma, authorities said.

The one victim who survived the shooting spree was airlifted to a hospital in Phoenix, about 160 miles to the northeast. That person's condition was not immediately known.

Krieger said City Hall and the local courthouse were shut down briefly as a security precaution after the shooting in town. A Yuma school official said three nearby elementary schools also were locked down for about two hours.

"It's a tragedy," the mayor said, adding that the shooting was especially troubling coming just five months after six people were killed and 13 others wounded, including Arizona Congresswoman Gabrielle Giffords, in a shooting rampage across the state in Tucson.

Geier told reporters at an early evening news conference that "many unanswered questions" remain about the shootings.

The city of Yuma normally averages no more than four homicides a year, Geier said.

(Additional reporting by Alex Dobuzinskis and Dan Whitcomb; Writing by Steve Gorman; Editing by Greg McCune)