Who killed the Palestinian driver of an aid truck and wounded two others as their convoy made its way into the Gaza Strip through the Erez crossing during Thursday's "humanitarian cease-fire?" According to the foreign media, who based their information on UN sources, IDF tank shells blasted the truck. According to the Magen David Adom medic who claimed to have taken the Palestinians to an Israeli hospital, the truck actually came under Hamas sniper fire. The medic, who asked not to be named, said he got his information from soldiers in the field, but by press time - some eight hours after the incident - the IDF Spokesman's Office was still unable to provide a response or to establish contact with the relevant sources in the field. Adding to the confusion, the Palestinian Red Crescent Society said it had evacuated the victims, but the MDA medic said soldiers told him they had gone in, at great personal risk, to evacuate the wounded Palestinians. What is certain is that there is one dead Palestinian, and two others being treated at Ashkelon's Barzilai Medical Center for gunshot wounds. The incident occurred Thursday afternoon at the Erez crossing into northern Gaza, the main entrance used by aid agencies to funnel badly needed food and medical supplies into the Strip. UN officials in New York placed the blame squarely on Israel, not just for the Erez incident, but also for a separate episode in which a marked UN ambulance convoy sent to retrieve the body of an UNRWA worker killed by an air strike came under small arms fire near Beit Hanun on Thursday afternoon. No one was injured in that incident. John Ging, the director of operations in Gaza for UNRWA, said via video link that "the verbal assurances have run out in terms of credibility." "We cannot rely on firm commitments given from the Israeli side," Ging told reporters. "To have Israeli forces on the ground firing at and now hitting convoys that have been specifically cleared - this is real-time clearance?" Ging acknowledged, however, that he could not be absolutely certain that the attacks came from IDF forces, telling a reporter who asked whether other combatants may have been responsible, "There is a conflict going on." Nonetheless, John Holmes, the US's under secretary general for humanitarian affairs, called Israel's UN ambassador to register a formal complaint about the failure of the Israeli humanitarian liaisons to guarantee safety for UN convoys. A spokeswoman for the Israeli mission, Mirit Cohen, confirmed that Ambassador Gabriela Shalev had spoken with Holmes and expressed "sympathy" for the deaths of UN staff. "This is a tragic event, but this is what happens during a [military] operation," Cohen told The Jerusalem Post. As a result of the incident, the United Nations Relief and Works Agency (UNRWA) said it was suspending operations relating to the collection and distribution of humanitarian aid. But here, too, there seemed to be confusion. Richard Miron, the chief UN spokesman in Israel, told the Post that UNRWA was not suspending all of its operations, but just those relating to humanitarian aid. "It's too dangerous and our staff are not safe," he said, adding that UNRWA would still be operating its schools and other centers in Gaza. Miron's comments to the Post came after Adnan Abu Hasna, the agency's Gaza-based spokesman, said that UNRWA had decided to suspend all its operations in the Strip because of the increasing hostile actions against its premises and personnel. Earlier, Miron was quoted by the London Times's Web site as saying that the IDF had been notified in advance about the UNRWA convoy, "which was hit as it approached the Erez crossing with Israel." Miron later told the Post that the UN was not sure whether the truck had been going into or out of the Gaza Strip when it was attacked. He added that the UN believed the damage was caused by an IDF tank shell. Miron said the UN was not looking to assign blame to either side, but rather trying to make sure aid got to the people who needed it, and that attacks on humanitarian convoys from any source had to stop. The incident highlights the dangers involved in sending aid convoys through the crossings into the Gaza Strip. It also shows that the IDF Spokesman's Office is not always able to respond in good time to incidents of this nature. For at least seven hours, the international media were quoting a version of events that claimed the Palestinian truck driver was killed by an Israeli shell. The IDF Spokesman began fielding calls regarding the incident from the foreign press at about noon Thursday, and by 7 p.m. had still not been able to get a clear answer from IDF Southern Command. Peter Lerner, a Defense Ministry spokesman who responds to the international press on humanitarian issues, said six hours after the event that he was unaware of the incident, and referred queries to the IDF. According to MDA, the driver and two others, Palestinian civilians contracted by the UN, suffered gunshot wounds to the chest and upper body. In response to a Post query, a spokeswoman from Barzilai confirmed that the two surviving Palestinians were being treated for gunshot wounds. On Wednesday, Israel agreed to suspend offensive operations in Gaza between 1 p.m. and 4 p.m. to allow aid convoys in and for Gazans to be able to collect supplies. Hamas resumed firing rockets promptly at 4. Apart from the alleged sniper fire, on Thursday Hamas terrorists fired mortars at Israeli communities in the Gaza periphery not long after that day's humanitarian cease-fire had begun. Defense Ministry spokesman Lerner told the Post that Israel would continue to allow aid convoys in, despite the threat of shooting and hijacking by Hamas. Lerner added that the convoys and humanitarian cease-fires were an integral part of the IDF's operations in Gaza, to show that "the Palestinian people are not our enemy, Hamas is." Lerner said that while a small amount of humanitarian aid was pilfered by Hamas, the majority of it was getting through to Palestinian civilians. Allison Hoffman and Judy Siegel contributed to this report.