They conduct the operation with military precision. Nearly every school day, patrol cars sit bumper-to-bumper to the east of the school, then fan out, being stationed on the corners of each block leading to the African American part of town, near the Philadelphia city line.

From the moment the children leave the school, behaving and misbehaving as early adolescents do, police are circling them on bikes, telling them to move along or to stop being smart-mouthed or to get out of the street.

If there's a fight, officers sometimes bring out the police dogs.

Youths who don't stay on the sidewalk are cited for jaywalking and handed tickets carrying hefty $92 fines. The majority of those cited are African American, among them sixth graders Symira Henderson and Jameelah Burley, both 12 years old when they were ticketed in January. An 11-year-old classmate, whose parents did not want her name used, also got a ticket.

"It all happened so fast," said Jameelah, barely 5 feet tall, with an impish grin and stubby ponytail. She said she and her friends didn't mean to defy police, only get across the street.

As Philadelphia's older suburbs struggle to balance issues of crime and enforcement, race and class, these school-day patrols in Upper Darby open a window into the clashing perceptions of police and the black communities they say they are trying to protect.

Upper Darby police say the patrols have a simple goal: keeping kids safe.

"What happens is, the high school kids fight with the middle school kids, the middle school kids fight with the grade school kids," Chief Michael Chitwood said.

The patrols, begun in the early 1990s, are used only on the schools on the eastern side of town, where most African Americans live.

Chitwood shrugs off questions about whether the enforcement has a racial dimension, saying those streets are where the trouble starts.

"If it wasn't a problem, we wouldn't be out there," he said. "I have better things to do with my officers."

'Intimidating the children'

Yes, these adults say, the kids can get rowdy. But viewed through the lens of race and history, these patrols - dogs, a police cordon, officers writing tickets to preteenagers - stir feelings ranging from discomfort and resentment to anger.

The use of dogs is particularly sensitive, carrying unpleasant echoes of the civil-rights marches of the 1960s.

"That's just another way of intimidating the children," said Yeadon NAACP president Linda Osinupebi, whose chapter covers Upper Darby.

Jameelah, the 12-year-old, said the dogs terrified her when police had them at Beverly Hills early in June: "Soon as they brought the dogs out, I had to go."

Chitwood says that the dogs are used judiciously and that no child has ever been bitten. "If there is a large crowd, and there's going to be a fight, they take the dogs out," he said.

Parents say they, too, want their children safe - but worry that these patrols will boomerang and turn their children against police.

It may already be happening with Symira, a young girl who wears bright green sneakers with pink laces.