North Charleston police chased a vehicle to downtown Charleston on Monday morning, then lost sight of its driver when he fled the scene on foot.
A woman told police her boyfriend snatched her keys and got into her car after an argument.
The woman and her young children got into the car with her boyfriend on Furr Street and told him not to take her car, but he did so anyway, police said.
The woman called police from the car as her boyfriend sped off with her and her children on board, police spokesman Spencer Pryor said.
Police spotted the car on Interstate 26 and started following it, Pryor said. The man refused to pull over and reached speeds of 90 mph as he headed into Charleston, he said.
He finally pulled over at Romney and Simons streets in Charleston, where he jumped from the car and ran off, Pryor said.
Officers searched the area but could not find the man, Pryor said.
The woman and her two children were not injured, and she drove her car away from the scene, Pryor said.
Police did not identify the people involved in the incident.