OAKLAND — Two women were killed and at least three other women were wounded early Tuesday morning after someone opened fire on a party bus on an Oakland freeway, authorities said.

The Alameda County Coroner’s Bureau confirmed one woman died in the bus and the other at an Oakland hospital.

The shooting happened at about 12:20 a.m. on eastbound Interstate 580 near the Seminary Avenue off-ramp, as the party bus was returning to Oakland from San Francisco with a group celebrating a woman’s 21st birthday.

A gunman or gunmen in another vehicle began shooting at the bus on the freeway and the suspects followed the bus off I-580 and shot at them some more on city streets, near 68th Avenue and Foothill Boulevard, authorities said. Dozens of rounds were fired at the party bus.

At least three other women were wounded and taken by ambulance to a hospital from the Oakland Police Eastmont Substation, where the bus driver was able to drive to after the shooting.

Relatives who showed up at the Eastmont station told the Bay Area News Group one of the women killed was a 19-year-old Stockton resident. A man who identified himself as the father of the 21-year-old celebrating her birthday said she was shot in the leg but is in stable condition.

Following the gunfire, the California Highway Patrol shut down traffic on east I-580 at the MacArthur Boulevard exit. The lanes were reopened later Tuesday morning.

CHP is investigating the shooting and believe it was a targeted attack, although a motive is not yet known. Detectives are asking the public’s help in identifying the suspects and the suspect vehicle. Anyone with information is asked to call the CHP investigative tip line at 707-917-4491.

Last month, a 25-year-old woman was shot while riding on a party bus in East Oakland in the 7600 block of MacArthur Boulevard. Authorities said there were more than 30 passengers on the bus which was eventually supposed to go to San Francisco. None of the other passengers or the driver were injured and the woman survived the April 9 shooting.

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