The children most at risk of attempted abduction by strangers are girls ages 10 to 14, many on their way to or from school, and they escape harm mostly through their own fast thinking or fierce resistance, according to a new national analysis.

Probing a crime that is infrequent but strikes fear in the hearts of parents as little else does, analysts from the National Center for Missing & Exploited Children found that children who encountered would-be abductors were usually alone, often in the late afternoon or early evening.

It’s a chilling thought for working parents and all those who have asked children to hold hands tightly in crowds or to phone as soon as they get home from school. It calls to mind last year’s killing of Somer Thompson, 7, snatched en route from school in Florida as she ran ahead of her siblings, and the highly publicized case of Elizabeth Smart, taken from her Utah bedroom at age 14.

The new analysis examines more than 4,200 cases of abductions that were attempted but not successful, and it shows that children were their own best protectors.

“They escaped these things not through the efforts of good Samaritans, but through recognizing a bad situation and either getting away from it, avoiding it or screaming and kicking to draw attention,” said Ernie Allen, president of the missing children’s center.

In the vast majority of the cases examined, children escaped harm through their own actions. In 16 percent of the cases, an adult stepped in to help.

“The goal here is not to frighten, but to encourage parents to sit down with their kids, talk to them about their safety, and practice these things,” he said. “Our overall premise is, kids protect themselves with their heads, and if they are prepared and alert, and if they know what to do and how to respond, they are at far less risk.”

Allen said parents should be aware that children targeted in abduction attempts are often preteens and teens in middle grades. More than 70 percent were girls.

Federal studies have found that teenagers are most at risk in nonfamily abductions.

Older children may be targeted more because they are less likely to be supervised, Allen said, and girls may be more often targeted by sexual predators.

Federal research shows successful abductions by strangers are relatively rare; an estimated 115 a year nationally involve children transported 50 miles or more and held at least overnight by a stranger in a classic kidnapping case.

An additional 21,500 stranger abductions involve other circumstances, according to Justice Department statistics. About 36,700 other abduction cases a year involve a caretaker, neighbor or someone a child knows at least casually.