A United Nations agency's suspension Friday of aid into Gaza is the latest in a series this week of tougher stances against Hamas — in contrast to the U.N.'s criticisms of Israel during its battle with Hamas in Gaza in late December and January.

The suspension of aid was in response to armed Hamas militants on Thursday stealing hundreds of tons of food intended for Palestinians by armed Hamas militants.

Also this week, the U.N. reversed its earlier claims that Israeli Defense Forces had bombed a school in Gaza administered by the United Nations Relief Works Agency (UNRWA). On Tuesday, the U.N.'s Office for Humanitarian Affairs issued a report on the Jan. 6 incident that claimed the lives of 43 Palestinians, stating that "the shelling, and all of the fatalities, took place outside rather than inside the school."

Separately, Radhika Coomaraswamy, U.N. special representative for children and armed conflict told the Jerusalem Post on Thursday that the organization will investigate the use by Hamas of children as human shields during the three-week Israeli military operation in Gaza.

Though the U.N. as recently as Thursday criticized Israel, for the seizure of a shipment bound for Gaza, its rhetoric against the Jewish state has softened considerably. Its statements on the Jan. 6 shelling, for example, had set off talk of potentially trying Israeli leaders in European domestic courts under "universal jurisdiction" for war crimes.

Click to view photos from the conflict.

IDF officials said at the time of the shelling that their soldiers were returning fire at Hamas militants launching mortars. UNRWA, however, focused blame for the attacks squarely on the Jewish state. "Those in the school were all families seeking refuge," said UNRWA's director of Gaza operations John Ging said immediately afterward. "There's nowhere safe in Gaza."

Following an investigation conducted by the Toronto Globe and Mail late last month, UNRWA officials acknowledged that no one inside the school died. An UNRWA spokesman told the paper that it had not claimed that people inside the school had died, but a UN report days later said that the school was "directly hit."

Throughout the three-week conflict, UNRWA offered little public criticism of Hamas. In an interview last month with FOXNews.com, an UNRWA spokesman acknowledged that the agency's facilities and aid shipments did not enjoy armed security. He claimed that armed security was not needed because the agency had successfully employed "moral suasion" with Hamas to convince the terrorist group that any actions against UNRWA would harm Palestinian aid recipients.

"If someone came in with guns," the UNRWA spokesman explained, "the people inside would probably kick him out."

Twice this week, Hamas gunmen have stolen emergency aid shipments in Gaza.

On Tuesday, 3,500 blankets and over 400 food parcels were taken at gunpoint in Beach Camp, Gaza. Then on Thursday, 10 truckloads of flour and rice were stolen, again at gunpoint.

"Hamas knows very well what they have to do if they want us to resume aid into Gaza," UNRWA spokesman Christopher Gunness said in an interview with FOXNews.com. "The aid must be returned and we must be given credible assurances from Hamas that there will be no repeat of these thefts." He added, "This is a very strong position."

After the looting of blankets and food, but before the second theft, Ging, UNRWA operations director, strongly criticized Hamas' actions. Noting that while Hamas leaders were largely underground, he said that "those above ground seem bent on acting in a reckless manner."

UNRWA's criticisms of Hamas were welcomed on Capitol Hill, but they are unlikely to quell efforts to bring greater oversight and accountability of the agency. Over 40 members of Congress now have signed onto a letter to Secretary of State Hillary Clinton calling for an independent audit of UNRWA. The letter was drafted by Reps. Mark Kirk, R-Ill., and Steve Rothman, D-N.J.

"It's an agency that's increasingly held in disrepute on Capitol Hill," Kirk said. "But this new posture may be an effort to forestall an independent audit."

Kirk is also a co-sponsor of legislation introduced last week by Rothman calling for greater transparency at UNRWA, insisting that the agency put its textbooks on the Internet and screen its payroll against terrorist databases of members of Hamas, Islamic Jihad and other Palestinian-based organizations. UNRWA admitted to FOXNews.com that it currently only screens its employees against a watchlist of roughly 500 Taliban and Al Qaeda operatives, most of whom live in Afghanistan and Pakistan.

"When it comes to fighting terrorist organizations, it's better late than never," Kirk said.

He added that he long had been miffed by what he believes has been UNRWA's ambivalence toward Hamas.

"I always wondered why the United Nations didn't address an entity dedicated to the destruction of a member nation of the U.N.," he said. "You think it would be basic that a U.N. agency would defend the existence of members of the U.N."