HAWARA CHECKPOINT, West Bank (AP) - A 16-year-old Palestinian with a suicide bomb vest strapped to his body was caught at a crowded West Bank checkpoint Wednesday, setting off a tense encounter with Israeli soldiers whom the army said he was sent to kill.

The soldiers, taking cover behind concrete barriers, sent a yellow army robot to bring scissors to the teenager so he could cut off the vest. They then made him strip to his underwear to ensure he was unarmed before detaining him.

There was no immediate claim of responsibility for the latest in a series of foiled attacks on Israel by Palestinian youths.

The family of the teenager, identified as Hussam Abdo, said he was gullible and easily manipulated.

"He doesn't know anything, and he has the intelligence of a 12 year old," said his brother, Hosni.

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 an oversized red jersey, approached them.

"We saw that he had something under his shirt," said Lt. Tamir Milrad. The soldiers took cover behind concrete barricades, pointed their guns at the teenager and ordered him to stop.

On their orders, he took off his jersey, revealing a bulky gray bomb vest.

"He told us he didn't want to die. He didn't want to blow up," Milrad said.

The soldiers sent a small robot to hand Abdo scissors to cut off the vest, an incident captured in exclusive Associated Press Television News footage.

The teenager 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.

The military said Abdo's mission was to kill soldiers at the crowded checkpoint.

"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.

Abdo, though 16, looked far younger, and the Israeli military initially said it believed he was 10 years old.

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."

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 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.

They said he acted strangely Tuesday, giving candy to his family and neighbors and refusing to explain why.

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.