JERUSALEM — Moshe Klein, a 46-year-old school principal, was about to complete his army reserve duty when he joined a group of Orthodox volunteers that gathers the remains of people blown apart in terrorist bombings.

Since then, he's learned the art of removing his mind from the task at hand. "In these situations, there's no time for feelings. The heart is full, but the hands are busy," he says.

"I climb on ladders and, with my knife in hand, scrape off flesh and blood. You separate yourself from it, you work like a robot."

In the aftermath of each suicide bombing, Israelis' eyes remain focused on television images, and ears stay fixed to radio broadcasts, listening and looking on in horror.

Police and rescue workers, their faces struggling to remain impassive, carry out their task of separating the living from the dead.

In the background, the blackened skeleton and empty seats of yet another bus are a potent reminder of how quickly tragedy can strike. And dispersed throughout the scene are the black kippot and orange vests of Chesed Shel Emet (True Mercy), the volunteer group that includes Klein.

The charedi, ultra-religious men, are fulfilling a holy act, a mitzvah. Respect for the dead is one of the holiest imperatives incumbent upon the Jewish people.

There is no greater deed than carrying out the rituals and customs pertaining to death. Yet whoever imagined that caring for the dead would translate into gathering body parts and skin fragments from trees and balconies?

"It's a holy act," says Rabbi Elazar Gelbstein, director of Chesed Shel Emet. "God created us in his image and we must do his deeds. This is our job. It's hard and it breaks us but it must be done."

Gelbstein cuts an imposing figure, tall, with bushy gray eyebrows and a full beard. He sits at his desk, which is covered with papers and an overflowing ashtray, surrounded by stacks of files, a computer and constant interruptions from his assistants.

Yet he speaks in gentle tones, and his eyes are red-rimmed as he recalls his experiences. "I remember after the 405 [Jerusalem-Tel Aviv bus attack in 1989], I didn't talk at home for a few days," he says, pausing for control.

"When a reporter on the scene asked me how I was doing, I started crying and continued for 10 minutes. It was probably better that he asked me, rather than holding it inside."

The 405 bus attack in the summer of 1989 was a turning point in the formation of Chesed Shel Emet. Originally, the task of gathering body remains had fallen to the police and other rescue organizations.

That fall, the municipality turned to Gelbstein, who was active in the Jerusalem Chevra Kadisha (one of the community organizations that tend to the rituals of death), and asked him to help organize a society that would teach volunteers how to undertake the task.

At the first meeting, relates Gelbstein, there were 20 or 30 people.

He found them by word of mouth and through ads placed in the neighborhood newspapers. About a third came back after the first meeting, with two-thirds lost to scheduling conflicts and an understandable discomfort or fear with the job at hand.

When Klein went to the first basement meeting in 1989, the group was shown films from various bombings, footage too shocking to be shown on television. Many participants didn't return: If they couldn't handle the film, how could they deal with the real thing?

The group grew slowly over the course of a year, attending classes taught by the police, army personnel, medical staff and rabbis. The 180 volunteers are all charedi men, some of whom have served in the army, as well as pacifists of varying stripes, from left-of-center to the right, from pro-settlement to anti-settlement.

Gelbstein says there was a need to find common ground: Each participant was doing this service to help others regardless of his political viewpoints.

"We started learning, building a torah of information on the subject," says Gelbstein.

"How, why, how many…how to find it, carry it. What are the guidelines, how to gather everything and get it to the right places.

"How to list, photograph, who took it, where did they take it to. We did all kinds of exercises, using dolls, watching films, practice runs at the airport, at the railway station."

The group taught a course in Bnei Brak, at the request of Ashkenazi Chief Rabbi Yisrael Meir Lau, and now there are Chesed Shel Emet outlets in several cities. Gelbstein would like to see them all under one umbrella organization.

At the No. 5 bus bombing on Dizengoff Street in Tel Aviv in October 1994, the Jerusalem men worked side by side with those from Bnei Brak, some of them arriving on the scene after hearing the news on the radio.

One of the requirements is that the volunteers themselves be married. The philosophy is that an unmarried male is, first and foremost, tied to his studies in the yeshiva, and not mature or responsible enough to deal with the situation.

The volunteers come from a variety of occupations: rabbis, teachers, a doctor, lawyers, shopkeepers and retirees.

Most of them carry their own beepers or cellular phones, and Gelbstein uses those instruments to help contact members. He laments the inevitably inefficient logistics of the system. Many times he simply grabs the vests and runs to the site where the others are already waiting.

"We basically pick up the phones, if there's time," he explains. "But often, there's not. With Sunday's bombing, I heard about it at 7 a.m., and there wasn't one person who hadn't heard about it."

After Monday night's bombing in Tel Aviv, according to the Los Angeles Times, Avishai Nagar, a nurse, rushed to help with the Hesed shel Emet tasks. "You want each body piece you find to be the last one, but then there is another and another, and it is not the last one and there is yet another," the Times quoted her.

When their work is done, the volunteers try to talk about the experience, although members rarely find the time.

Klein says he doesn't generally talk about his work. The day following the No. 18 bombing people commented on his demeanor, however.

"That's unusual, because I'm a good actor. But it's difficult to hide this kind of stuff," he says.

"At night, in bed, that's when you're alone with your thoughts and images. You try to run from your thoughts but it's a constant replay in front of your eyes. You can attempt to get over it but the heart is full."

Gelbstein, according to the Times, adds that "you try with all your will to reconstruct [a bombing victim]. You cannot get into this person's spiritual parts, but you try to reconstruct the physical side…You try to find everything that belongs to him."

Participants, he says, are well aware of the reasons they carry out this difficult work.

"This is what makes us a Jewish nation, this type of experience that doesn't differentiate between us," he says.

"We do it from our heart and soul. It's a hard chesed, a difficult deed, but we must overcome it because God gave us the strength."