Shirley Deanna Smith, 30, was an innocent bystander, police said.
Smith, called "Dee" by her friends, died at Highland Hospital less than one hour after the shooting and doctors were unable to save her 16-week-old fetus.
Police said Smith was shot at 1:36 a.m. on the 200 block of Webster Street after she and her boyfriend and other friends left Mingles nightclub. They had attended a local rapper's birthday party at the club, along with scores of people, some from as far away as Sacramento and Stockton.
While walking down the block to Smith's Range Rover, two rival groups shot at each other and Smith was hit, police said.
Casings lay scattered for more than a block, and the suspects fled.
It is unclear what may have
prompted the shooting, but police said it could have been the result of an earlier argument at the club.
"The two groups started shooting at each other, and (Smith) was just caught in the middle. She was an innocent bystander," Homicide Sgt. Derwin Longmire said. "That woman, she didn't deserve that. It's sad she was killed, but what makes it even more tragic is that her unborn child also died."
People in an East Oakland apartment where police said Smith lived, declined to comment Saturday. Attempts to reach a man believed to be her boyfriend were unsuccessful.
Smith's two children are in foster care, a spokesman at the Alameda County Coroner's Office said.
Smith, who may have been trying to seek cover when she was hit, collapsed on the sidewalk. A woman who did not know Smith gave her CPR until paramedics arrived and took her to Highland Hospital, where she died at 2:11 a.m.
A woman believed to have been grazed by one of the shots appeared later at a San Francisco hospital, but was extremely uncooperative, police said. She said she had been at Minglesearlier that night, but insisted she was injured because someone threw something at her, police said.
No other wounded people have been found, police said.
A sport utility vehicle parked in the 200 block of Webster was hit by gunfire, as was a Honda Accord on the 100 block.
Smith's death brings Oakland's homicide tally for the year to 131.
Police and the Alameda County District Attorney's office have not yet decided whether the unborn fetus's death should be classified as a homicide.
Police and Crime Stoppers of Oakland are offering up to
$25,000 in reward money for information leading to the arrest of the suspects. Anyone with information is asked to call police at (510) 238-3821 or Crime Stoppers at (510) 238-6946.
The shooting was at least the third this year linked to Mingles.
On April 17, high school basketball star Ronald Hall Jr., 18, was fatally shot while sitting in a parked car on the 200 block of Webster Street. A 24-year-old man was also wounded in the shooting.
Police believe Hall was an innocent victim struck by an errant round after a brawl outside the club.
On March 17, a 22-year-old Pittsburg man told police he was shot in the face while leaving the club and claimed he did not know why.
Police and residents have been calling on Mingles to stop the violence occurring outside its doors or face possible closure.
Calls to Mingles were not returned Saturday.
Staff writers Kristin Bender and Grace Rauh contributed to this report.