The Israelis dashed behind concrete barricades, pointed their guns at the youth and ordered him to stop. On their instructions, he took off his jersey, revealing a bulky, gray bomb vest - and setting off a tense encounter captured in exclusive Associated Press Television News footage.
"He told us he didn't want to die. He didn't want to blow up," said Lt. Tamir Milrad.
Members of the al-Aqsa Martyrs' Brigades in the Balata refugee camp next to Nablus claimed responsibility for the latest in a series of foiled attacks on Israel by Palestinian youths. Al-Aqsa is loosely linked to Yasser Arafat's Fatah movement.
The family of the teenager, identified as Hussam Abdo, said he was gullible and easily manipulated.
"He doesn't know anything (about politics), and he has the intelligence of a 12 year old," said his brother, Hosni.
Abdo, though 16, looked far younger, and the Israeli military initially said it believed he was 10. His family said he acted strangely Tuesday, giving candy to them and to neighbors and refusing to explain why.
Since the Israeli assassination of Hamas spiritual leader Sheik Ahmed Yassin on Monday, Israel has been on high alert. Hamas has killed hundreds of Israelis in suicide bombings and other attacks in recent years.
Wednesday's confrontation began about 4 p.m. when soldiers at the Hawara checkpoint outside Nablus received intelligence a bomber was there. They shut down the crossing and began searching hundreds of people there, the military said.
Suddenly Abdo, wearing the jersey, approached them.
"We saw that he had something under his shirt," Milrad said.
The soldiers, taking cover behind the barriers, sent a yellow army robot to bring scissors to the teenager so he could cut off the vest.
Abdo, visibly frightened and confused, cut off part of the vest and struggled with the rest. "I don't how to get this off," he said in frustration before successfully removing it.
Soldiers ordered him to take off his undershirt and pull down his jeans to make sure he had no other weapons. Then they arrested him.
Sappers blew up the vest, which the army said was an 18-pound bomb.
Abdo told the soldiers who caught him that someone gave him $23, a suicide bomber's vest, and then sent him to go kill Israelis, reported CBS News Correspondent David Hawkins.
"In addition to the fact that he would have harmed my soldiers, he would have also harmed the Palestinians waiting at the checkpoint, and there were 200 to 300 innocent Palestinians there," said the commander of the checkpoint, who identified himself only as Lt. Col. Guy.
Several teenagers have carried out suicide bombings over the past 3 1/2 years, and there has been recent concern that militant groups were turning to younger attackers to elude Israeli security checks.
On March 16, Israeli troops stopped an 11-year-old boy allegedly trying to smuggle explosives through the same checkpoint. Israel said militants had given the boy the explosives without his knowledge, either to ferry across the checkpoint or to be blown up by remote control when he got near soldiers.
Palestinians and the boy disputed this, claiming the bag he was carrying - which was blown up by army sappers - contained auto parts.
Last month, Israeli police arrested three boys, aged 12, 13 and 15, who said they were on their way to carry out a shooting attack in Israel.
"No matter how many times Israel learns of the use of children for suicide bombings, it is shocking on each occasion," said Dore Gold, an adviser to Israeli Prime Minister Ariel Sharon. "Israelis do not understand how Palestinians are willing to sacrifice their own children in order to kill ours."
Many, if not most, Palestinians are also shocked by the use of children by terrorists -- but try to put it in context.
"As long as the Intifada is going on, as long as the incidents are escalating and the level of violence is escalating, we will have children who are ready to become martyrs, who are ready to become suicide bombers," Palestinian psychiatrist Dr. Iyad Zaqout told Hawkins.
Physicians for Human Rights also condemned the militants' use of children, calling it "illegal and immoral."
After the incident Wednesday, the army brought out Abdo, who appeared shaken but defiant, to be photographed by the media.
Reporters were allowed only to ask his name, age and grade.
Maj. Sharon Feingold, an army spokeswoman, said reporters were not allowed to question the youth "for intelligence reasons." An inquiry was under way, she said, "to find out who sent this boy and why they did it. Naturally this is a monstrous doing of evil people, sending young children and turning them into human bombs. It's horrid and terribly worrisome."
Abdo's family said the teenager was not affiliated with any militant group, going to rallies for all of them and identifying with whichever one carried out the latest attack on Israelis.
On Tuesday, he got his hair cut in the style his mother, Tamam, likes and told her he would do anything she wants, she said.
"You never are like this," she said "What happened?"
"I just want you to be happy with me," he responded.
Abdo left his house Wednesday morning saying he was going to school, but never arrived there.
Hosni Abdo said he was furious with whoever persuaded his brother to strap on the bomb vest.
"The ones who sent him are stupid, because the army will give him two slaps and he will tell them who sent him," Hosni Abdo said.