It's been one week since the bomb attack on the United Nations headquarters in Baghdad that killed at least 23 people and wounded more than 80 others. U.N. offices have re-opened and many staff members have returned to work. But the grief and emotional scars from the attack will take much longer to heal.

A worker shovels debris into a basket under the scorching sun in a late morning at the U.N. compound in Baghdad. A forklift passes by, carrying a stack of smashed computers. Beside the damaged building, makeshift offices have been set up in several dozen tents and [cargo] containers. Staff members come and go, sometimes stopping to hug each other. Some confer on the dirt walkways, preferring the open air to the stifling heat in the tents.

The World Food Program was one of the U.N. agencies headquartered here. WFP Spokesman Khaled Mansour shows a reporter the effects of the bombing, as trucks continue to haul debris away.

"This was the entrance to the building," said Mr. Mansour. "You can see through the building because of the force of the blast. This was our cafeteria where we had dinner. A couple of people died in that cafeteria because of the blast."

Mr. Mansour makes his way past rows of smashed U.N. vehicles to the corner of the building that took the full force of the blast. This area housed the office of senior U.N. representative Sergio Vieira de Mello, who was killed in the attack. Most of the rubble has been cleared and the remains of the offices are now exposed, like the rooms of a doll house.

"This is precisely where the office of [U.N. special representative] Sergio [Vieira] de Mello was," he pointed out. "It's not there anymore. This was the second floor. This was conference room here. And the third floor had Mr. de Mello's office.

The WFP is responsible for delivering food that is distributed to millions of Iraqi's who sunk into poverty because of international economic sanctions imposed 13 years ago and decades of economic mismanagement by the Saddam regime. The sanctions were imposed to prevent the ousted President Saddam Hussein from rebuilding his military forces after his disastrous invasion of Kuwait.

Mr. Mansour says the attack on the U.N. headquarters has hurt WFP operations, but he says it will not disrupt the food pipeline. He says Iraqi groups that distributed the food have stepped in to help.

"Yes, we have been impacted," added Mr. Mansour. "We had to evacuate, like, 40 percent of our staff members in Baghdad out of the country. But we still have enough staff to do all the essential food pipeline operations. Because here we are providing about half-a-million tons of food every month to sustain this gigantic food rationing system. That will not be affected."

The blast that devastated the senior U.N. leadership in Iraq is also being felt at other agencies, like the United Nations Childrens Fund. UNICEF is based in another part of the city, but its 31-year-old coordinator of operations was at the headquarters when the bomb struck and died in the attack.

UNICEF Communications Director Geoffrey Keele says his friend's death has affected the agency's operations in two ways.

"One is that we're all in shock and we lost one of our best friends and a very good colleague in this attack and people are really just trying to recover from that," said Mr. Keele. "Also security is going to have to be increased dramatically. We had what I felt were decent security measures before the war, but that was because we were thinking about different kinds of potential threats."

Many aid organizations operating in Baghdad have received threats. These have led them to tighten security and re-evaluate their staffing levels. But no organization has announced plans to leave Iraq, yet. WFP's Khaled Mansour says most U.N. workers remain committed to the task of helping Iraq's re-build their country.

"Yes, our compound has been destroyed, but you see us working in tents and containers turned into offices," he said. "More than 60 percent of the staff that were here during the blast are still here, continuing with their work."

At the site of the explosion, the U.N. field officer Nicolaas Rademeyer oversees the release of the remains of the bombing victims to their families. He says the mood has changed, but the determination to help remains.

"The mood a few days ago was demoralized, terrible, but you can see people are coming back," said Mr. Rademeyer. "People are glad to see one another, recognize one another. So, the mood is definitely changing and we've made our mind up. We are not going to leave Iraq. We are here to help the people of Iraq. We are not going to allow radical people to control us. Yes, so we are in for a difficult time, but we are here to stay."

Similar expressions of commitment are heard across the international aid community. But concern is also rising that continued indiscriminate attacks will delay the return to stability and economic recovery that Iraqis so desperately want.