The first victim was killed at 1:29 a.m. in the 27000 block of Orlando Avenue, Hayward police Lt. Chris Orrey said.
A man was shot and killed while sitting in a parked car with several associates, she said.
The group was sitting in the car when a second vehicle drove by and a passenger fired into the parked car, striking and killing the man. Twenty minutes later, a second homicide was reported in the 22000 block of South Garden Avenue, according to Orrey.
A group of four people was walking toward a parked car when a second group confronted them, she said. A member of the confronting group pulled a gun and fired at the foursome, hitting one man.
The victim and his three associates fled on foot, but the victim collapsed and eventually died from his injuries.
Orrey said no suspects had been identified or arrested as of 5:45 a.m. Sunday.
Detailed descriptions of the suspect vehicles were not immediately available, she said, but investigators were still conducting interviews. They hoped to have more details later today.