Two women were killed while five other passengers were wounded during a shooting incident where authorities believe at least two suspects opened fire at a party bus driving down a San Francisco freeway on Tuesday.

The party was celebrating the 21st birthday of one woman in the bus shortly before the attackers opened fire at around 12:20 a.m. The vehicle was driving down Interstate 580 while making its way from San Francisco to Oakland.

Party Bus Shooting

Officials said at least two suspects who were inside another car started shooting at the bus. They then followed the party vehicle on the freeway and continued their assault on city streets. Authorities said about 70 rounds of bullets were fired at the victims.

“Based on preliminary investigation, it does not appear this shooting was a random event,” the California Highway Patrol said as it continued investigations with the help of Oakland police.

One woman died after being shot while on the bus and the other died while being treated at the hospital, the Alameda County Coroner’s Bureau said. Relatives of one of the victims said she was a 19-year-old Stockton resident.

Authorities said at least five other women were injured during the shooting and immediately transported to the hospital. One of the victims was reportedly in critical condition due to their wounds. One man who identified himself as the father of the 21-year-old birthday celebrant said his daughter was shot in the leg but was in stable condition.

Oakland authorities said a 25-year-old woman was shot last month while riding on a party bus. The vehicle had more than 30 passengers who were going to San Francisco. Fortunately, officials said there were no injuries other than the woman who survived her wounds, the Associated Press reported.