The incidents happened near the Mary Bethune School at 3301 Old York Road, and the most recent attempt happened just on Monday.
Police say it was at 8:10 a.m. when an 8-year-old boy was walking in the 1000 block of West Venango Street when a man, wearing a ski mask, grabbed his book bag and pulled the child toward him.
The boy's sister rushed over and freed the boy, police said, but the suspect then grabbed the girl by the hair, pulling her toward him.
Police say other children nearby started throwing rocks at the man, knocking him down. He then got up and ran away as the girl escaped.
The suspect in this incident was described as a black male with dark complexion wearing a black ski mask, dirty blue jeans that were cut up, and black and blue Lebron James soldier sneakers.
The previous incident happened just outside the school at 3:15 p.m. on Wednesday, February 19th.
According to police, a 10-year-old girl said she was walking home from school when she was approached by a man, wearing a ski mask, who grabbed her by the arm.
The girl kicked the man, police say, who got into a small, four-door light brown vehicle and drove away.
The girl said she saw the man again the next day outside her school, talking to another student.
The suspect in this incident was described as a black male with a thin build, wearing all-black clothing, black gloves and a ski mask.
Action News was on the scene as Philadelphia Police investigators searched a home in the area looking for the suspect. Police believe they know who he is but have not been able to locate him.
The search remains active.
"I walk my kids to school so I don't let them come to school alone, because that is the type of thing that I worry about," said Cynthia Williams.
Parents in the neighborhood say they planned to be on the alert.
"My daughter is 13 but still, I will be watching and tell other parents to watch also, because I don't want anything to happen to our kids," said Wanda Clay.
"Imagine if it happened to me or somebody I know, that would drive me crazy. So it's recommend to every parent, walk the kid home and pick them up," said Jose Gonzalez.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.