BY JULIE WATSON
  Associated Press

  NOGALES, Mexico - The giggly 12-year-old boy's feet were giving out. The gallon jugs of water he carried in each hand banged against his tired legs. He
  fell four times, scraping his knees. Cactus spines poked through his high-tops and pricked his feet.

  Luis Alberto Damian tried not to think about any of that. Instead, he would recount later, he tried to focus on keeping up with the 19 migrants marching
  ahead of him into the inky night -- and on his mother, who was waiting for him at the end of his journey.

  But after 15 hours of walking through North America's harshest desert, his trip would be in vain: Luis Alberto was

  among nearly 35,000 children arrested this year while illegally crossing the U.S.-Mexico border.

  Activists say kids like Luis Alberto drive home the urgent need for a migration accord between Mexico and the United States. Both governments promised
  this month to resume talks, sidelined since the Sept. 11 terrorist attacks.

  Meanwhile, tens of thousands of children cross every year -- many accompanied only by strangers on the most treacherous trip of their lives. Most
  children, like Luis Alberto, are headed to see parents living illegally in the United States.

  In the past, migrants often used false passports and birth certificates to get their children across the border.

  But closer scrutiny by officials since Sept. 11 has made that nearly impossible, experts say, and many migrants prefer to have their children smuggled
  rather than leave U.S. jobs to return to Mexico for them.

  Experts fear the heightened security is forcing children to embark on perilous journeys.

  ''It seems the only way is crossing through the desert,'' said Candelaria Cruz, coordinator of a government shelter for deported Mexican children in
  Nogales, across from Nogales, Ariz.

  Since security was heightened, U.S. Border Patrol arrests have dropped to their lowest level in more than a decade. But the death toll has varied little --
  indicating that those who are crossing are taking more dangerous routes.

  The Border Patrol registered 320 deaths in the fiscal year that ended in September, compared with 336 in 2001.

  The Border Patrol does not track individuals' ages, but the Foreign Relations Department reports four children under 15 died this year, compared with
  one last year. ''We've seen a lot of kids this year under 10 years old, like 2, 4, 6 and 7,'' said Fernando Guerrero, the Nogales shelter's night supervisor.

  Luis Alberto, who suffered only scrapes and bruises, was among the lucky ones.

  Some children have arrived at the shelter barefoot and so badly blistered that the skin on the soles of their feet has peeled off, Guerrero said.

  The worst case the shelter has seen was an 8-year-old boy found huddled under a tree after wandering alone in the desert for three days, abandoned
  by a smuggler.

  ''When he arrived, he was hallucinating,'' Cruz said. ``He would dream he was in an ocean, he was so dehydrated.''

  Before the Mexican government opened the shelters along the 2,000-mile border in 1999, the Border Patrol handed all children over to Mexican police in
  border cities, who simply released them.

  The shelters arrange for relatives to get the children. Still, most try to cross again.

  Luis Alberto and his 17-year-old brother crossed the border at the Tohono O'odham Indian reservation west of Nogales and hiked into the desert with
  the group. When they reached a ranch house, he said, smugglers separated the brothers onto two trucks waiting to take them on the next leg of their
  journey. Luis Alberto squeezed down on the floor behind the driver's seat. After reaching the highway, the truck stopped amid frantic whispers. Everyone
  scrambled. Luis Alberto was the only one caught.

  He slept on the floor of a U.S. immigration detention center. The next day, Border Patrol agents handed him to Mexican police in Nogales, who took him to
  the shelter.

  From there, he called his mom, an illegal immigrant in Atlanta. Asked what his mom told him, the boy said: ``She told me not to worry. She talked to the
  smuggler, and I can try again.''