The incidents occurred near Sylmar High School and Olive Vista Middle School. The youngest girl was 12.
Police say a man in his early 20s tried to lure one girl into his car, which was described as a black 1995 Toyota Camry with a partial license plate ending in 880.
In each case, the suspect circled the block looking for victims and then called out to them from the car or approached them on the sidewalk, police said.
The suspect was described as heavy set, medium height, with short hair.
Los Angeles Police Department officials believe they're closing in on a suspect but anyone with information was urged to call Crime Stoppers at (800) 222-TIPS.