FREMONT -- Two of three family members struck by a car on a Centerville district sidewalk have been released from the hospital, police said Thursday.

A 43-year-old woman and her 3-year-old son were released Wednesday evening from Eden Hospital in Castro Valley, said police spokeswoman Geneva Bosques. The woman's 1-year-old daughter was kept overnight for observation.

It was not immediately known if the infant had been released Thursday.

Both the woman and her daughter suffered serious head injuries when a white 2000 Nissan Maxima hit the family as the woman stood with her daughter in a stroller on a sidewalk at the intersection of Fremont and Peralta boulevards, police said. The 3-year-old was standing beside his mother when the Maxima struck them. He was not hurt, but was taken to the hospital with his mother.

The daughter was taken to Children's Hospital in Oakland.

Police identified the driver of the car who hit the family as 21-year-old Joseph Ansari of Union City. Ansari was treated at a Washington Township Hospital in Fremont for minor injuries, then arrested Wednesday upon his release on suspicion of reckless driving causing bodily injury and taken to Santa Rita Jail.

He posted bail and had been released Thursday morning.

Ansari was driving a the Maxima west on Fremont Boulevard when he got into an argument with another motorist near the intersection of Fremont Boulevard and Mowry Avenue, said police Detective Bill Veteran

While the other motorist slowed down, police said Ansari kept going, traveling above the speed limit along Fremont Boulevard, though police said they didn't know exactly how fast. As he approached Peralta Boulevard, Ansari lost control of the Maxima, police said, and hit the mother and children on the sidewalk.

"(He) tries to make a right turn, goes up on the sidewalk, hits a light pole then strikes the woman and her two children," Veteran said.

Both vehicles stopped after the collision, police said.

The accident remains under investigation. Anyone with information is asked to contact the Fremont Police Traffic Unit at 510-790-6760.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund