Modesto police said a woman was killed Friday night when a vehicle struck her on a central Modesto off-ramp of Highway 99. Police said the incident was an assault.

It occurred at 8:50 p.m. on the northbound Highway 99 offramp at Sixth Street. Emergency responders performed CPR on the woman. She was taken to a hospital where she died from her injuries, Officer Adam Foster of Modesto police said.

Police said Saturday that detectives are conducting a homicide investigation. There was no information on whether an arrest was made.

Witnesses told the California Highway Patrol that the vehicle had been northbound on the highway and turned onto the central Modesto exit. According to preliminary information, witnesses said the woman, who was on foot, was screaming before she was struck by the vehicle.

The driver sped away. Police didn’t release information on the suspect vehicle. The woman’s name was not released.

Anyone with information about the incident is asked to call Modesto Detective Randy Bolinger at 209-342-9162.

The Modesto Bee will have more on this story, as details are released.